Download CE-PHY II - MECHANICS

HKCEE 1990 – 1998
PHYSIC – Multiple Choices
Mechanics
(90-CE-PHY II - 1)
1.
The above graph shows how the square of velocity of an object undergoing uniform acceleration
varies with displacement. The object is initially at rest and travels along a straight line.
The acceleration of the object is
A.
0.5 ms-2
B.
1.0 ms-2
C.
2.0 ms-2
D.
4.0 ms-2
E.
8.0 ms-2
(90-CE-PHY II - 2)
2.
A block of mass 5 kg is moving horizontally on a smooth surface in a straight line at 6 ms In
order to change its speed to 10 ms-1, the work done would need to be
A.
40 J.
B.
90 J.
C.
160 J.
D.
400 J.
E.
550 J.
(90-CE-PHY II - 3)
3.
A trolley moves with constant speed along a horizontal surface. A lump of plasticine having the
same mass as the trolley is dropped onto the trolley and sticks to it. Which one of the following
ticker-tapes best represents the motion of the trolley ?
A.
B.
C.
D.
E.
(90-CE-PHY II - 4)
4.
Y has a linear relationship with time as shown. Y may represent
(1)
the speed of a body starting from rest under a constant force.
(2)
the distance travelled by a body at constant speed.
(3)
the acceleration of a body falling from rest.
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(90-CE-PHY II - 5)
5.
A solid cube exerts a pressure P on the table. What is the pressure exerted by another cube of the
same material but with all the dimensions doubled ?
A.
P
4
B.
P
2
C.
P
D.
2P
E.
4P
(90-CE-PHY II - 6)
6.
Two objects P and Q, of mass 0.1 kg and 0.5 kg respectively, are thrown vertically upwards with
the same speed from the same level. Neglecting air resistance, which of the following is true ?
A.
P will reach a point higher than that of Q.
B.
Q will take a shorter time to reach its highest point.
C.
Both will have the same potential energy at the highest point.
D.
Both will have the same kinetic energy on returning to the starting point.
E.
Both rise with the same deceleration.
(90-CE-PHY II - 7)
7.
Which of the following statements is/are correct when a collision between two particles is
elastic ?
(1)
None of the original kinetic energy is converted into other forms of energy.
(2)
The linear momentum of each particle is conserved.
(3)
The mechanical energy of each particle is conserved.
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(90-CE-PHY II - 8)
8.
A small metal ball is released from a point above the floor and bounces several times. Which of
the following graphs best represents the variation of the velocity of the ball with time ?
A.
B.
C.
D.
E.
(90-CE-PHY II - 9)
9.
In the figure, the uniform metre rule of weight 1N is balanced horizontally. Find the tension T in
the string.
A.
2.4 N
B.
3.4 N
C.
8.4 N
D.
9.4 N
E.
22 N
(90-CE-PHY II - 10)
10.
When two objects are immersed in a liquid, their loss in weight is the same. These two objects
must have the same
A.
mass.
B.
volume.
C.
density.
D.
weight in air.
E.
weight in the liquid.
(91-CE-PHY II - 1)
1.
Which of the following is/are vectors ?
(1) momentum
(2) kinetic energy
(3) potential difference
A. (1) only
B. (2) only
C. (1) and (3) only
D. (2) and (3) only
E. (1), (2) and (3)
(91-CE-PHY II - 2)
2.
Two blocks of equal mass are placed on a smooth horizontal surface as shown above. A constant
force of 12 N is applied to block A so that the two blocks move towards the right together. The
force acting on A by B is
A.
zero.
B.
6 N to the left.
C.
6 N to the right.
D.
12 N to the left.
E.
12 N to the right.
(91-CE-PHY II - 3)
3.
For a body falling freely under gravity, Y has a linear relationship with the displacement of the
body as shown above. Y may represent
A.
the potential energy of the body.
B.
the kinetic energy of the body.
C.
the acceleration of the body.
D.
the velocity of the body.
E.
the speed of the body.
(91-CE-PHY II - 4)
4.
The figure above shows the strobe photograph of a ball rolling down a slope. The stroboscope is
flashing at a frequency of 5 Hz. Find the acceleration of the ball.
A.
0.20 ms-2
B.
0.50 ms-2
C.
0.67 ms-2
D.
1.00 ms-2
E.
1.33 ms-2
(91-CE-PHY II - 5)
5.
The above figure shows the velocity-time graph of an object. Which of the following statements
about the object is/are true ?
(1)
Its acceleration in the first 10 seconds is 2 ms-2
(2)
The total distance travelled is 250 m.
(3)
It returns to its starting point after 25 seconds.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(91-CE-PHY II - 6)
6.
A block is pulled along a horizontal bench at a constant velocity of 10 ms -1 by a force of 5 N.
What is the work done against friction in 4 seconds ?
A.
200 J
B.
50 J
C.
20 J
D.
12.5 J
E.
8J
(91-CE-PHY II - 7)
7.
The diagram above shows the variation of the net force acting on an object which is initially at
rest. Which of the following velocity-time graphs correctly describes the motion of the object ?
A.
B.
C.
D.
E.
(91-CE-PHY II - 8)
8.
A gas molecule collides with the wall of a container and bounces back with the same speed.
Which of the following quantities of the molecule remain(s) unchanged before and after the
collision ?
(1)
kinetic energy
(2)
velocity
(3)
momentum
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(91-CE-PHY II - 9)
9.
A force F is applied to a block of mass 1 kg as shown above. The GREATEST value of F for the
block to remain at rest is 11 N. What would be the motion of the block if F is not applied ?
A.
remaining at rest
B.
sliding down with constant velocity
C.
sliding down with an acceleration of 1 ms-2
D.
sliding down with an acceleration of 5 ms-2
E.
sliding down with an acceleration of 6 ms-2
(91-CE-PHY II - 10)
10.
A man of weight W stands inside a lift which is moving upwards with a
the force exerted by the poor on the man is R, which of
constant speed. If
the following statements is/are
correct ?
(1)
R is greater than W in magnitude.
(2)
R and W are in opposite directions.
(3)
R and W form an action and reaction pair according to Newton's third law.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(91-CE-PHY II - 11)
11.
Two particles A and B of masses 2 kg and 1 kg respectively move in opposite directions. The
initial velocity of A is 4 ms-1 towards the right, while that of B is 2 ms-1 towards the left. They
collide head on. After the collision, the velocity of A becomes 1 ms-1 towards the RIGHT. What
would be the velocity of particle B ?
A.
2 ms-1 towards the right
B.
3 ms-1 towards the right
C.
4 ms-1 towards the right
D.
6 ms-1 towards the right
E.
7 ms-1 towards the right
(92-CE-PHY II - 1)
1.
Which of the following displacement-time graphs describes the motion of a particle moving in a
straight line with uniform deceleration ?
A.
B.
C.
D.
E.
(92-CE-PHY II - 2)
2.
A man takes 2 seconds to walk from point A to point B, and then takes 3 seconds to walk from
point B to point C, where ABC is an equilateral triangle of side 3 m. Find the magnitude of his
average VELOCITY from A to C.
A.
0.60 ms-1
B.
1.00 ms-1
C.
1.20 ms-1
D.
1.25 ms-1
E.
1.50 ms-1
(92-CE-PHY II - 3
3.
(1)
(2)
(3)
The above tape charts represent the motion of a trolley coasting downhill on different slopes.
The frequency of the ticker-tape timer remains unchanged. Arrange the tape charts in ascending
order of the accelerations of the trolley.
A.
(1), (2), (3)
B.
(2), (1), (3)
C.
(2), (3), (1)
D.
(3), (1), (2)
E.
(3), (2), (1)
(92-CE-PHY II - 4)
4.
Figure (a)
Figure (b)
Figure (a) shows a man near the edge of a cliff projecting a stone vertically upwards. The stone
reaches the sea after 18 seconds. Figure (b) shows the velocity-time graph for the motion of the
stone. Find the height of the cliff.
A.
180 m
B.
540 m
C.
720 m
D.
900 m
E.
1620 m
(92-CE-PHY II - 5)
5.
A trolley of mass 2 kg moves with a uniform speed of 4 ms' along a horizontal table. A lump of
plasticine having the same mass as the trolley is dropped from a height slightly above the trolley
and sticks to it. Find the total loss in kinetic energy.
A.
0J
B.
4J
C.
8J
D.
12 J
E.
16 J
(92-CE-PHY II - 6)
6.
A ball is released from rest from one end of a smooth curved rail as shown in the above diagram.
Neglecting air resistance and friction, which of the following statements about the motion of the
ball is/are correct ?
(1)
The ball has maximum kinetic energy at point B.
(2)
The speed of the ball at point C is the same as that at point A.
(3)
The ball would not rise to a level higher than point D.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(92-CE-PHY II - 7)
7.
Which of the following involve(s) an energy transfer of 100 J ?
(1)
A mass of 10 kg is raised vertically by 10 m.
(2)
A mass of 2 kg gains a speed of 10 ms-1 from rest.
(3)
A 10 W heater is switched on for 10 seconds.
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(92-CE-PHY II - 8)
8.
Two identical blocks X and Y are connected by a light string passing over a smooth pulley as
shown above. The two blocks are released from rest. After a while, the string breaks. Which of
the following correctly describes the motion of the blocks immediately after the string breaks ?
X
Y
A.
stops moving
accelerates at 5 ms-2
B.
moves with constant velocity
accelerates at 5 ms-2
C.
accelerates at 5 ms-2
moves with constant velocity
D.
moves with constant velocity
accelerates at 10 ms-2
E.
decelerates at 5 ms-2
accelerates at 10 ms-2
(92-CE-PHY II - 9)
9.
In the above diagram, blocks A and B are connected by a light inextensible string and rest on a
smooth horizontal table. The masses of A and B are 2 kg and 3 kg respectively. Block A is
pulled by a force of 2 N. Find the tension in the string S.
A.
0.4 N
B.
0.8 N
C.
1.0 N
D.
1.2 N
E.
2.0 N
(92-CE-PHY II - 10)
10.
Which of the following pairs of forces F, and F, is/are action and reaction pair(s) according to
Newton's third law of motion ?
(1)
(2)
(3)
F1 =
Weight of the block
F2 =
Reaction from the floor
F1 =
Weight of the ball
F2 =
Tension in the string
F1 =
Electric force acting on
the negative charge
F2 =
Electric force acting on
the positive charge
A.
(2) only
B.
(3) only
C.
(1) and (2) only
D.
(1) and (3) only
E.
(1), (2) and (3)
(92-CE-PHY II - 11)
11.
The above diagram shows a light rod under the action of three vertical forces. The points P, Q, R,
S and Tare equally spaced along the rod. At which point must an upward vertical force of 2 N be
applied to hold the rod in equilibrium ?
A.
P
B.
Q
C.
R
D.
S
E.
T
(92-CE-PHY II - 12)
12.
A screw jack is used to lift a load of 4000 N by an effort of 20 N, as shown in the above diagram.
The pitch of the screw is 2 x 10-3 m and the length of the handle is 0.25 m. Find the efficiency of
the screw jack.
A.
0.5 %
B.
9.9 %
C.
25.5 %
D.
50.9 %
E.
62.5 %
(92-CE-PHY II - 13)
13.
In the above diagram, the displacement can is filled with water up to the level of the spout. The
readings of the balances A and B are 5 N and 15 N respectively. The metal block is then
completely immersed in the water without it touching the can. Find the readings of the balances.
(Given : volume of metal block = 1 x 10-4 m3, density of water = 1000 kg m-3)
Balance A
Balance B
A.
4N
15 N
B.
4N
16 N
C.
4N
19 N
D.
5N
15 N
E.
5N
20 N
(93-CE-PHY II - 1)
1.
Which of the following pairs of physical quantities has/have the same unit?
(1)
Work and potential energy
(2)
Moment and momentum
(3)
Specific heat capacity and specific latent heat of fusion
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(93-CE-PHY II - 2)
2.
The above paper tape is obtained from a trolley moving with uniform acceleration. The
frequency of the ticker-tape timer is 50 Hz. Find the acceleration of the trolley.
A.
0.2l m s-2
B.
0.70 m s-2
C.
0.73 m s-2
D.
1.05 m s-2
E.
2.10 m s-2
(93-CE-PHY II - 3)
3.
An object is thrown vertically upwards from a point A. It travels to the highest point B and then
falls back to A. Neglecting air resistance, which of the following statements is/are true ?
(1)
The total displacement of the object is zero.
(2)
The acceleration of the object is constant throughout the motion.
(3)
The time for the upward motion is longer than the time for the downward motion.
A.
(I)only
B.
(3) only
C.
(I)and (2) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(93-CE-PHY II - 4)
4.
The figure above shows the variation of the force acting on an object. What physical quantity
does the area of the shaded portion represent ?
A.
Velocity
B.
Acceleration
C.
Momentum
D.
Work
E.
Power
(93-CE-PHY II - 5)
5.
The above diagram shows the variation of the acceleration of an object which is initially at rest.
Which of the following velocity-time graphs correctly describes the motion of the object ?
A.
B.
C.
D.
E.
(93-CE-PHY II - 6)
6.
A pendulum bob is released from rest from a point P 0.8 m above its lowest position e, as shown
in the above diagram. Neglecting air resistance, find the speed of the bob when it reaches q.
A.
2.8 m s-1
B.
4 m s-1
C.
8 m s-1
D.
16 m s-1
E.
It cannot be determined since the mass of the bob is not given
(93-CE-PHY II - 7)
7.
A pulley system is used to raise a load upwards by 2 m. The input energy is 5000 J. If the
efficiency of the pulley system is 80%, find the load.
A.
2000 N
B.
3125 N
C.
4000 N
D.
6250 N
E.
8000 N
(93-CE-PHY II - 8)
8.
A piece of ice floats in water as shown above. Which of the following statements is/are true ?
(1)
The density of ice is smaller than the density of water.
(2)
The weight of water displaced by the ice is equal to the weight of ice.
(3)
The volume of water displaced by the ice is equal to the volume of ice.
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(1) and (3) only
E.
(2) and (3) only
(94-CE-PHY II - 1)
1.
Which of the following is a correct unit for the corresponding physical quantity ?
Physical quantity
Unit
A.
Work
watt
B.
Upthrust
kilogram
C.
Momentum
newton second
D.
Heat capacity
joule per kilogram
E.
Electromotive force
newton
(94-CE-PHY II – 2)
2.
A trolley is given a push and runs down a friction-compensated runway. The motion of the
trolley is recorded on the paper tape as shown above. Which of the following changes can
enable the trolley to produce a paper tape as shown below ?
(1)
Giving the trolley a harder initial push
(2)
Increasing the angle of inclination of the runway
(3)
Increasing the frequency of the ticker-tape timer
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(94-CE-PHY II – 3)
3.
A man takes 30 s to walk 80 m towards the east. He then takes 10 s to run 60 m towards the
south. Which of the following statements is/are correct ?
(1)
The magnitude of the resultant displacement of the man is 140m.
(2)
The average speed of the man is 4.3 m s-1.
(3)
The magnitude of the average velocity of the man is 2.5 m s-1.
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(94-CE-PHY II – 4)
4.
Two blocks X and Y of weights 2 N and 8 N respectively are suspended by two light strings as
shown above. A downward force of 4 N is applied to X. Find the tensions T 1 and T2 in the two
strings.
T1 T2
A.
2N
8N
B.
4N
10 N
C.
4N
14 N
D.
6N
12 N
E.
6N
14 N
(94-CE-PHY II - 5)
5.
A solid rectangular block of dimensions 3 cm x 4 cm x 5 cm exerts a pressure P on a horizontal
table when it stands on face X as shown above. What is the pressure exerted by the block on the
table if it stands on face Y?
A.
5 P
3
B.
5 P
4
C.
P
D.
4 P
5
E.
3 P
5
(94-CE-PHY II - 6)
6.
A man of mass 50 kg is standing in a lift. If the lift is falling freely, which of the following
statements is/are true ?
(1)
The weight of the man is 0 N.
(2)
The force acting on the floor of the lift by the man is 500 N.
(3)
The force acting on the man by the floor of the lift is 0 N.
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(94-CE-PHY II - 7)
7.
The above diagram shows a light rod under the action of two vertical forces. Under which of the
following conditions will the rod be in equilibrium ?
A.
Applying an upward force of 2 N at P
B.
Applying a downward force of 2 N at P
C.
Applying an upward force of 4 N at R and a downward force of 4 N at Q
D.
Applying an upward force of 4 N at P and a downward force of 4 N at R
E.
There is no need to apply any more force as the rod is already in equilibrium
(94-CE-PHY II - 8)
8.
A screw jack is used to raise a load of 6000 N upwards by 0.3 m. If the efficiency of the jack is
40%, find the input energy.
A.
720 J
B.
2400 J
C.
4500 J
D.
8000 J
E.
500001
(94-CE-PHY II - 9)
9.
A stone is projected vertically upwards. Neglecting air resistance, which of the following graphs
shows the variation of the kinetic energy of the stone with the distance travelled during its
upward motion ?
A.
B.
C.
D.
E.
(94-CE-PHY II - 10)
10.
Two blocks X and Y are connected by a light string passing over a smooth pulley as shown
above. The mass of X is greater than that of Y. The two blocks are released from rest. Which of
the following statements is/are correct ?
(1)
The potential energy lost by X is equal to the potential energy gained by Y.
(2)
The kinetic energy gained by X is greater than the kinetic energy gained by Y.
(3)
The potential energy lost by X is equal to the sum of kinetic energies gained by X and Y.
A.
(2) only
B.
(3) only
C.
(1) and (2) only
D.
(1) and (3) only
E.
(1), (2) and (3)
(95-CE-PHY II - 1)
1.
Which of the following pairs of physical quantities has the same units ?
A.
Charge and current
B.
Frequency and time
C.
Kinetic energy and heat
D.
Moment and momentum
E.
Work and potential difference
(95-CE-PHY II - 2)
2.
smooth horizontal surface
In the above diagram, the two blocks are connected by a light string S. They move with uniform
acceleration of 2 m s-2 under the action of a constant force F. What will the accelerations of the
blocks become if S suddenly breaks ?
2 kg block
4 kg block
A.
6ms-2
0ms-2
B.
6ms-2
2ms-2
C.
2ms-2
0ms-2
D.
2ms-2
2ms-2
E.
0ms-2
3ms-2
(95-CE-PHY II - 3)
3.
A stone is thrown vertically upwards and it finally falls back to the starting point. Assume air
resistance is negligible. Which of the following statements is/are true throughout the motion ?
(1)
The acceleration of the stone is constant.
(2)
The total energy of the stone is conserved.
(3)
The momentum of the stone is conserved.
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
E. (1), (2) and (3)
(95-CE-PHY II - 4)
4.
An object starts from rest and moves with uniform acceleration along a straight line. Which of
the following graphs concerning the motion of the object is/are correct ?
(s = displacement, v = velocity, r = time)
(1)
(2)
(3)
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(95-CE-PHY II - 5)
5.
Two objects of different masses are released from rest at the same height. Assume air resistance
is negligible. Which of the following statements is/are correct ?
(1)
A greater gravitational force is acting on the object with greater mass.
(2)
They take the same time to reach the ground.
(3)
They have equal velocities when they reach the ground.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(95-CE-PHY II - 6)
6.
A trolley is placed on a horizontal ground. A force F inclined at an angle  to the horizontal acts
on the trolley. What is the horizontal component of F that pulls the trolley towards the right ?
A.
F
B.
F sin
C.
F cos
D.
F
sin 
E.
F
cos 
(95-CE-PHY II - 7)
7.
A car moves with a speed 30 km h-1. The driver applies the brake and the car is stopped in a
distance of 12 m. If the car is moving at 60 km h-1, what is the stopping distance ? Assume that
the same constant braking force is applied in both cases.
A.
12 m
B.
24 m
C.
48 m
D.
72 m
E.
96 m
(95-CE-PHY II - 8)
8.
The above diagram shows the variation of the velocity of an object with time. What is the
distance travelled by the object in the first 3 seconds ?
A.
5m
B.
15 m
C.
25 m
D.
30 m
E.
45 m
(95-CE-PHY II - 9)
9.
Figure (a)
Figure (b)
A bullet of mass 0.02 kg travelling at 450 m s-1 enters a wooden block as shown in Figure (a)
and leaves it with a speed 400 m s-1. In Figure (b), what is the maximum number of identical
blocks that the same bullet can pass through ?
A.
3
B.
4
C.
5
D.
9
E.
10
(95-CE-PHY II - 10)
10.
A trolley runs down a friction-compensated runway as shown above. Which of the following
statements is true ?
A.
The kinetic energy of the trolley increases with time.
B.
The potential energy of the trolley increases with time.
C.
The sum of kinetic and potential energies of the trolley remains unchanged.
D.
The frictional force acting on the trolley is zero.
E.
The resultant force acting on the trolley is zero.
(95-CE-PHY II - 11)
11.
The above diagram shows a block resting on the ground.
Let W
be the weight of the block,
F
be the gravitational force acting on the earth by the block, and
R
be the force acting on the block by the ground.
Which of the following pairs of forces is/are action and reaction pair(s) according to Newton's
third law of motion ?
(1)
R and W
(2)
W and F
(3)
F and R
A.
(1) only
B.
(2) only
C.
(3) only
D.
(1) and (2) only
E.
(2) and (3) only
(95-CE-PHY II - 12)
12.
Which of the following is/are the advantage(s) of using method (1) to lift the load over method
(2)?
(1)
The input energy required is smaller.
(2)
The effort required is smaller.
(3)
The distance travelled by the effort is smaller.
A.
(2) only
B.
(3) only
C.
(1) and (2) only
D.
(1) and (3) only
E.
(1), (2) and (3)
(1996-CE-PHY II - 2)
2.
A man walks 40 m towards the west. He then walks 40 m towards the south and lastly
walks 70 m towards the east. Find the magnitude of the resultant displacement of the
man.
A.
30 m
B.
40 m
C.
50 m
D.
70 m
E.
150 m
(1996-CE-PHY II - 3)
3.
Which of the following statements about mass and weight is incorrect ?
A.
Mass is measured in kilograms and weight in newtons.
B.
Mass is a scalar while weight is a vector.
C.
Mass is a measure of the inertia of an object and weight is a measure of
the gravitational pull on it.
D.
The weight of an object at a particular place is proportional to its mass.
E.
Both the mass and weight of an object vary slightly at different places on
the earth.
(1996-CE-PHY II - 4)
4.
An object moves with uniform acceleration along a straight line. Which of the
following graphs correctly describe(s) the motion of the object ?
(1)
(2)
(3)
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(1996-CE-PHY II - 5)
5.
Which of the following statements concerning the motion of an object is/are correct ?
(1)
A constant unbalanced force is needed to keep an object moving with uniform
velocity.
(2)
An increasing unbalanced force is needed to keep an object moving with uniform
acceleration.
(3)
An object may remain at rest if there is no unbalanced force acting on it.
A.
(2) only
B.
(3) only
C.
(1) and (2) only
D.
(1) and (3) only
E.
(1), (2) and (3)
(1996-CE-PHY II - 6)
6.
A coin and a feather are released from rest in vacuum as shown above. Which of the
following is/are correct deductions from this experiment ?
(1)
The masses of the coin and the feather are identical in vacuum.
(2)
The coin and the feather fall with the same acceleration in vacuum.
(3)
The forces acting on the coin and the feather in vacuum are identical.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(1996-CE-PHY II - 7)
7.
A motor car of mass 2500 kg accelerates from rest to a speed of 20 m s -1 in 5 s on a
level road. Find the average power of the car.
A.
10 kW
B.
50 kW
C.
100 kW
D.
200 kW
E.
250 kW
(1996-CE-PHY II - 8)
8.
A block remains at rest on an inclined plane as shown above. Which of the following
statements is/are true ?
(1)
The frictional force acting by the plane on the block is zero.
(2)
The normal reaction acting by the plane on the block is zero.
(3)
The resultant force acting on the block is zero.
A.
(2) only
B.
(3) only
C.
(1) and (2) only
D.
(1) and (3) only
E.
(1), (2) and (3)
(1996-CE-PHY II - 9)
9.
A uniform plank AB of weight 200 N rests on two trestles as shown above. A boy
stands at the end B of the plank. What can the maximum weight of the boy be without
tilting the plank ? (Assume the weight of the plank acts through its centre.)
A.
75 N
B.
100 N
C.
200 N
D.
300 N
E.
600 N
(1996-CE-PHY II - 10)
10.
The above diagram shows a man lifting a ball vertically upwards with uniform
acceleration.
Let F1 be the force acting on the ball by the man,
F2 be the force acting on the man by the ball,
F3 be the gravitational force acting on the ball.
Which of the following correctly describes the relation between the magnitudes of the
forces ?
A.
F1 = F2 > F3
B.
F1 = F3 > F2
C.
F1 > F2 = F3
D.
F1 > F2 > F3
E.
F1 > (F2 + F3)
(1997-CE-PHY II - 2)
2.
A student walks along a curve ABC , which is made up of two semi-circular parts AB
and BC of radius 3 m and 4 m respectively. He takes 2 s to walk from A to B and 5 s to
walk from B to C. Find the magnitude of the average velocity of the student from A to
C.
A.
1.0 m s-1
B.
2.0 m s-1
C.
2.3 m s-1
D.
3.l m s-1
E.
3.6 m s-1
(1997-CE-PHY II - 3)
3.
A block is placed on a smooth inclined plane. A force P parallel to the inclined plane is
applied to the block so that the block moves up the plane. Which of the following
diagrams correctly shows all the forces acting on the block ?
A.
B.
C.
D.
E.
(1997-CE-PHY II - 4)
4.
Which of the following physical quantities is not a vector ?
A.
Acceleration
B.
Momentum
C.
Velocity
D.
Weight
E.
Work
(1997-CE-PHY II - 5)
5.
A particle of mass m is thrown vertically upwards with initial speed v. When the
particle returns to its starting point, what are the changes in momentum and kinetic
energy of the particle ?
Change in momentum Change in kinetic energy
A.
0
0
B.
0
mv2
C.
mv
1
mv2
2
D.
2mv
0
E.
2mv
mv2
(1997-CE-PHY II - 6)
6.
A particle is released from rest and falls vertically under gravity. If the distance
travelled by the particle in the 1st second is x and that travelled in the 2nd second is y,
find the ratio x :y.
A.
1:1
B.
1:2
C.
1:3
D.
1:4
E.
1:5
(1997-CE-PHY II - 7)
7.
A pendulum bob is suspended by a light inextensible string. The bob is released from
rest at a point A as shown above. When the bob reaches the lowest point B, the string
hits a fixed pin. Which of the following statements is/are correct ?
(1)
The bob has maximum kinetic energy at B.
(2)
The highest level that the bob can reach is the level of the pin.
(3)
The work done by the tension of the string is zero throughout the motion.
A.
(2) only
B.
(3) only
C.
(l) and (2)only
D.
(l) and (3) only
E.
(1), (2) and (3)
(1997-CE-PHY II - 8)
8.
A machine lifts up a load of 1200 N to a height of 1.5 m in 2 s. Find the average output
power of the machine.
A.
400 W
B.
900 W
C.
1800 W
D.
3600 W
E.
9000 W
(1997-CE-PHY II - 9)
9.
Which of the following pairs of forces is/are action and reaction pair(s) according to
Newton's third law of motion ?
(1)
The weight of a man
and
standing on a chair.
(2)
(3)
The force acting on the
man by the chair.
The gravitational force
and
The gravitational force
acting on the earth by
acting on the moon by
the moon.
the earth.
The force exerted by a
and
The force exerted by the
swimmer on the water to
water
push
swimmer forward.
the
water
to
push
the
backward.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(1997-CE-PHY II - 10)
10.
A light plank of length 2 m rests on two trestles S1 and S2 as shown above. A boy of
weight 500 N stands at the mid-point of the plank. Find the forces acting on the two
trestles by the plank.
Force acting on S1
A.
166
2
N
3
Force acting on S2
1
333 N
3
B.
200N
300N
C.
250N
250N
D.
300N
200N
E.
1
333 N
3
166
2
3
N
(1998-CE-PHY II - 2)
2.
A car undergoes uniform deceleration along a straight road. Its velocity decreases from
30 m s-1 to 20 m s-1 after travelling a distance of 100 m. How much further will the car
travel before it comes to a rest ?
A. 50 m
B. 80 m
C. 180 m
D. 200 m
E. 300 m
(1998-CE-PHY II - 3)
3.
A block is pulled by a constant force and moves along a smooth horizontal surface.
Which of the following describes the variations of the acceleration and momentum of
the block during the time when thee force is acting ?
Acceleration
Momentum
A.
remains unchanged
remains unchanged
B.
remains unchanged
increases
C.
increases
remains unchanged
D.
increases
increases
E.
decreases
increases
(1998-CE-PHY II - 4)
4.
The velocity-time graph of a car travelling along a straight horizontal road is shown
above. Which of the following graphs shows the variation of the acceleration a of the
car with time t ?
A.
B.
C.
D.
E.
(1998-CE-PHY II - 5)
5.
At time t = 0, a table–tennis ball is released from a point above the ground and
bounces several times on the ground. The above graph shows the variation of the
velocity v of the ball with time t. (Note: Velocity pointing upwards is taken to be
positive.) At which of the following points on the graph does the ball reach its
maximum height above the ground after the first rebound ?
A.
Point P
B.
Point Q
C.
Point R
D.
Point S
E.
Point T
(1998-CE-PHY II - 6)
6.
A broken-down car of mass 1000 kg is pulled by a tow-truck and moves at a
constant velocity 8 m s-1 along a horizontal road. It is known that the frictional
force acting on the car is 500 N. Find the tension in the cable connecting the
truck and the car.
A.
0N
B.
500 N
C.
8 000 N
D.
8 500 N
E.
10 500 N
(1998-CE-PHY II - 7)
7.
Two forces F1 and F2 act on a particle P as shown above. If a third force F3 acts on P to
keep it in equilibrium, find the magnitude of F3.
A.
1.4 N
B.
4.0 N
C.
4.2 N
D.
4.5 N
E.
5.8 N
(1998-CE-PHY II - 8)
8.
A girl in a lift uses a spring balance to measure the weight of an object. The reading of
the spring balance is 10 N when the lift is at rest. When the lift is moving, the reading
of the spring balance becomes 8 N. Which of the following describes the motion of the
lift ?
A.
moving upwards with a uniform velocity
B.
moving downwards with a uniform velocity
C.
moving upwards with an acceleration
D.
moving downwards with an acceleration
E.
moving downwards with a deceleration
(1998-CE-PHY II - 9)
9.
Which of the following phenomena can be explained by Newton’s first law of motion ?
(1)
A passenger in a car tends to move forward when the car suddenly stops.
(2)
A coin and a feather fall with the same acceleration in a vacuum.
(3)
A gun recoils when it fires a bullet.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
E.
(1), (2) and (3)
(1998-CE-PHY II - 10)
10.
A man pulls a 50 kg block up a smooth inclined plane making an angle 30° with the
horizontal as shown above. The inclined plane is 6 m long and the block is pulled from
the bottom of the inclined plane to the top in 30 s. Find the average useful output power
of the man.
A.
5W
B.
10 W
C.
50 W
D.
87 W
E.
100 W
(1998-CE-PHY II - 11)
11.
A uniform beam of length 3 m and weight 300 N lies on a horizontal ground. What
minimum vertical force must be applied to one end of the beam to just lift that end off
the ground ? (Assume the weight of the beam acts through its mid-point.)
A.
100 N
B.
150 N
C.
300 N
D.
450 N
E.
900 N
(1998-CE-PHY II - 12)
12.
The diagram above shows a screwjack used in lifting a load. Which of the following
can improve its efficiency ?
A.
using a longer handle
B.
using a lighter platform
C.
using a heavier base
D.
using a screw with a larger pitch
E.
using a screw with a small diameter