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PYP001 Major-II Exam Solution. Choice A is the correct Answer.
Q1.
A falling object is encountering air resistance. At the moment the object reaches its
terminal speed,
A)
B)
C)
D)
E)
the acceleration of the falling object is zero.
air resistance becomes zero.
the falling object starts to slow down.
the acceleration of the falling object is 10 m/s2.
the falling object starts to fall faster.
Q2.
An astronaut on a certain planet drops a 2-kg rock from rest. He notices that the
rock falls 2 m straight down in 1 s. The weight of the rock on that planet is
A)
B)
C)
D)
E)
8 N.
4 N.
20 N.
2 N.
Zero N.
Q3.
A push on a 1-kg brick accelerates it. Neglecting friction, to equally accelerate a
10-kg brick, one would have to push with
A)
B)
C)
D)
E)
10 times as much force.
just as much force.
one-tenth as much of force.
100 times as much force.
none of these.
Q4.
A 6-kg block placed on a smooth horizontal table is connected to another 4-kg
block by a light rope that passes over a frictionless pulley as shown in the figure.
As the rope becomes fully stretched and the 4-kg block starts to fall, its
acceleration is
Fig#
A) 4 m/s2.
B) 6 m/s2.
C) 10 m/s2.
D) zero m/s2.
E) none of these.
Q5.
A ball thrown straight upward takes 10 s to go up and return to the starting point.
Because of air resistance, the time taken by the ball to reach its maximum height
could be
A)
B)
C)
D)
E)
4 s.
5 s.
6 s.
7 s.
none of these.
Q6.
The force exerted on the tires of a car to directly accelerate it along a road is
exerted by the
A)
B)
C)
D)
E)
road.
tires
engine.
air.
none of these.
Q7.
Two balls of the same size and of different masses are dropped from a tall building
into the air at the same time and from the same height. Which of the following
statements is TRUE?
A) The lighter ball reaches its terminal speed first.
B)
C)
D)
E)
The heavier ball reaches its terminal speed first.
Both balls reach their terminal speeds at the same time.
Both balls have the same terminal speed.
None of these.
Q8.
A 2-kg object is resting on a table. The pull of Earth on the book is called an action
force. The reaction force is
A)
B)
C)
D)
E)
the pull of the book on Earth.
the normal force exerted by the table on the book.
the weight of the book.
the normal force exerted by the ground on the table.
none of these.
Q9.
Newton’s first law is also known as the law of
A)
B)
C)
D)
E)
inertia.
acceleration.
relative motion.
action and reaction.
dynamic equilibrium.
Q10.
An object has a mass of 1 kg and is moving north with a speed of 10 m/s. What is
the momentum of the object when it is measured by an observer inside a car
moving north with a speed of 10 m/s.
A)
B)
C)
D)
E)
Zero kg.m/s.
10 kg.m/s north.
20 kg.m/s north.
10 kg.m/s south.
20 kg.m/s south.
Q11.
A 0.1-kg object moving east with an initial speed of 100 m/s encounters a force of
1000 N directed west for a time of 0.001 second. The final momentum of the
object is
A) 9 kg.m/s east.
B)
C)
D)
E)
1 kg.m/s west.
9 kg.m/s west.
11 kg.m/s east.
1 kg.m/s east.
Q12.
Object A has mass M and object B has mass 4M. Starting from rest, objects A and
B are pushed by equal forces (equal magnitudes and same direction) for equal time
intervals on a horizontal frictionless surface. At the end of the push, compared to
the momentum of object A, the momentum of object B is
A)
B)
C)
D)
E)
the same.
twice as much.
half as much.
four times as much.
¼ as much.
Q13.
The head of a hammer can be tightened onto the wooden handle by banging the
bottom of the handle against a hard surface as shown in the figure. This is an
application of
Fig#
A) Newton’s First law of motion.
B) Newton’s Second law of motion.
C) Newton’s Third law of motion.
D) None of these.
E) Earth gravitational force.
Q14.
An object of mass 1 kg is thrown vertically upward from the ground and returns to
the ground after 10 s. Neglecting air resistance, what is the net impulse given to the
object?
A) 100 N.s down.
B)
C)
D)
E)
100 N.s up.
50 N.s down.
50 N.s up.
Zero N.s.
Q15.
A boy drops a ball of mass 0.5 kg. It hits the ground with a speed of 10 m/s and
bounces back with the same speed. The change in its momentum is
A)
B)
C)
D)
E)
10 kg.m/s up.
10 kg.m/s down.
5 kg.m/s up.
5 kg.m/s down.
0 kg.m/s.
Q16.
A 5000-kg railroad car collides and sticks to another 5000-kg stationary railroad
car. After collision, they move off together with a speed of 5 m/s. What was the
speed of the moving 5000 kg car before the collision?
A)
B)
C)
D)
E)
10 m/s.
5 m/s.
15 m/s.
2.5 m/s.
Zero m/s.
Q17.
An object of mass 1 kg is pushed up along a 5 m long incline to a vertical height of
1 m. The change in its potential energy is
A)
B)
C)
D)
E)
+10 J.
10 J.
+5 J.
5 J.
Zero J.
Q18.
A man uses stairs to carry a 10-kg suitcase from the ground floor to an upper level
that is 30 m higher. The amount of work done on the suitcase by the man is
A) 3000 J.
B)
C)
D)
E)
300 J.
30 J.
30000 J.
depends on the number of stairs.
Q19.
The weight of an object on an outer planet is 10 times less than its weight on Earth.
Compared to its kinetic energy on Earth, the kinetic energy of an object moving
with the same speed on the outer planet is
A)
B)
C)
D)
E)
the same.
10 times more.
10 times less.
100 times more.
100 times less.
Q20.
An object moving at a certain speed has a kinetic energy KE of 90 J. If its speed is
made 3 times smaller, what would the decrease in its KE be?
A)
B)
C)
D)
E)
80 J.
90 J.
30 J.
270 J.
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