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Question Sheet 1
Foundation Physics (13.1XA1)
1.
Sound travels at a constant speed of 343 ms-1 in the air. Approximately how much time
(in seconds) does it take for the sound of thunder to travel 1609 m (1 mile)?
2.
Two cities are 2.5 ´ 102 km apart. If it takes 2 hours and 10 minutes for a lorry to
travel between the two, what is its average speed?
3.
A train moves out of a station at a constant acceleration of 1.2 ms-2 . Assuming its
initial speed is zero, what is its speed after 20 s?
4.
An aeroplane coming into land, switches on reverse thrust once on the runway. Its
initial velocity is 2.7 ´ 102 ms-1, and the acceleration due to reverse thrust is -10 ms-2 .
What is its velocity after (a) 20 s and (b) 30 s?
5.
Suppose a car is travelling at 17.8 ms-1 and the driver sees a traffic light turn red. After
0.510 s has elapsed (the reaction time), the driver applies the brakes, and the car
accelerates at -6.20 ms-2. What is the stopping distance of the car, as measured from
the point where the driver first notices the red light?
6.
A cyclist is moving at 9 ms-1 when a pedestrian steps out in front of her, 10 m ahead.
After a 0.43 s reaction time, the cyclist applies the brakes, which provide an
acceleration of -5.1 ms-2. What is her velocity when she hits the pedestrian?
7.
A car is approaching traffic lights at 15 ms-1 when the driver sees them turn from green
to amber. He knows that he has only 2.5 s to travel the last 50 m through the lights, to
avoid setting off the traffic camera, and so he accelerates at 8 ms-2. Does he make it?
8.
A golf ball rebounds from the floor and travels straight upward with a speed of
5.0 ms-1. To what maximum height does the ball rise?
9.
A car drives off the edge of a cliff that is 54 m high. The police at the scene of the
accident notice that the point of impact is 130 m from the base of the cliff. How fast
was the car travelling when it went over the cliff?
10.
During a fireworks display, a rocket is launched with an initial velocity of 35 ms-1 at
an angle of 75° above the ground. The rocket explodes 3.7 s later. What is the height
of the rocket when it explodes?
11.
A Porsche 911 accelerates from rest to 27 ms-1 (60 mph) due north in 5.8s. The mass
of the car is 1400 kg. What is the magnitude and direction of the average net force that
acts on the Porsche?
12.
Two skaters, an 82 kg man and a 48 kg woman, are standing on ice. Neglect any
friction between the skates and the ice. The woman pushes on the man with a force of
45 N due East. Determine the accelerations (magnitude and direction) of the man and
the woman.
13.
A 36.50 kg sphere is acted upon by a 133.0 N force directed along the x-axis. What is
the magnitude of a second force directed along the y-axis, such that the sphere
experiences an acceleration of 3.960 ms-2 directed at an angle q above the x-axis?
14.
Our solar system is in the Milky Way galaxy. The nearest galaxy is Andromeda, a
distance of 2 ´ 1022 m away. The masses of the Milky Way and Andromeda galaxies
are 7 ´ 1041 kg and 6 ´ 1041 kg, respectively. Treat the galaxies as particles and find
the magnitude of the gravitational force exerted on the Milky Way by the Andromeda
galaxy.
15.
Mount Everest has an altitude of 8850 m above sea level. Approximately, what is the
ratio between the acceleration due to gravity on the mountaintop and that at sea level?
(Radius of the earth = 6.38 ´ 106 m)
16.
Two identical space probes, each of mass 2.00 ´ 104 kg are 'parked' close to each other
in outer space. If they are separated initially by 1.00 km, how long (in hours) will it
take for the distance between them to decrease by 1.00 m, due to gravitational
attraction? Assume that the probes behave as point particles and that the gravitational
force remains constant as the probes move closer to each other.
Section I
Each question is worth 5 marks
ALL questions should be attempted
[1]
A fairground attraction lets the passengers experience ‘free-fall’ by letting the seating
drop, from rest, for a distance of 50m before the brakes are applied. How long do the
passengers experience free-fall conditions? Assume g=9.8ms-1.
5
[2]
Explain what is meant by (i) velocity and (ii) displacement.
5
[3]
Two tugboats pull a barge at constant velocity. Each tugboat exerts a force F = 10kN
according to the diagram below. What is the drag force on the barge?
5
Tug
F
Barge
o
30
F
[4]
[5]
[6]
[7]
o
30
Tug
A 79kg skier rides a 2.2km long ski lift to the top of the mountain. The lift makes an
angle of 16.7° with the horizontal. What is the change in the skier’s gravitational
potential energy? Assume g=9.8ms-1.
5
A metal block of mass 1kg is sitting on a horizontal table. What is the normal force
exerted by the table on the block? Assume g=9.8ms-1.
5
Briefly describe one of the following methods of heat transfer: conduction, convection
or radiation.
5
Describe the Kelvin temperature scale and its relationship to the Centigrade scale.
5