# Exam questions

Topics: Force, Potential energy, Energy Pages: 6 (483 words) Published: March 6, 2015
﻿
1.Distance travelled can be found from the
Aarea under a velocity-time graph
Barea under an acceleration-time graph
(Total 1 mark)

2.The graph shows how velocity varies with time for an object.

The total distance travelled by the object in 4 s is
A20 m
B40 m
C60 m
D80 m
(Total 1 mark)

3.A car of known mass has a constant acceleration. The resultant force acting on the car can be found by applying ANewton’s first law
BNewton’s second law
CNewton’s third law
DStokes’s law
(Total 1 mark)

4.Which of the following is a scalar quantity?
Aacceleration
Bdisplacement
Cforce
Dwork
(Total 1 mark)

5.A car pulls a trailer of weight 2500 N with a force of 20 N for a distance of 8 km along a horizontal road.
How much work is done by the car in pulling the trailer?
A160 J
B20 000 J
C160 000 J
D20 000 000 J
(Total 1 mark)

6.A ball is thrown straight up in the air and caught when it comes down. Which graph best shows the velocity of the ball from the moment it is released until just before it is caught?

(Total 1 mark)

7.Newton’s third law tells us that
Aactions usually have a reaction
Bweight and normal contact force are always equal and opposite Cmoving with constant velocity is the same as being at rest Dforces always arise in pairs
(Total 1 mark)

8.Which set of quantities is all scalar?
Aacceleration, displacement, velocity
Benergy, mass, power
Cextension, force, gravitational potential energy
Dweight, kinetic energy, work
(Total 1 mark)

9.Champagne bottles are often opened by ‘firing’ the cork out of the bottle. The world record for the horizontal distance travelled by a fired cork is 53 m.

The high pressure inside the bottle produces an average force of 150 N on the cork as it leaves the bottle. This force acts on the cork over a distance of 2.5 × 10–2 m.
(a)Show that the work done on the cork is about 4 J.
..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2)

(b)Calculate the maximum speed at which the cork could leave the bottle.
mass of cork = 7.5 × 10–3 kg
..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... Speed = ....................................

(2)

(c)The cork is fired from ground level at an angle of 40° to the horizontal with a speed of 32 m s–1. (i)Show that the vertical component of the velocity is about 20 m s–1. ........................................................................................................................... ........................................................................................................................... (1)

(ii)Calculate the horizontal distance travelled by the cork through the air. ........................................................................................................................... ........................................................................................................................... ..............................................................................................................................