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PHYSICS IGCSE

FORCES - Part B

(Hooke's Law, Moments, Astronomy, momentum)
nebula

page 1

These questions are about a lorry stopping when a dog jumps out into the road.

The table below shows the speed of the lorry at a time after the dog has jumped out.

Velocity (m/s)
time (s)
20
0
20
0.2
20
0.4
16
0.8
12
1.2
8
1.6
4
2.0
0
2.4

 

mad_dog

1. What was the driver's 'thinking' time?
2. How far did the lorry travel in this time?

3. What was the driver's braking time?
4. Calculate the lorry's deceleration in m/s2.

5. What 2 factors could have affected the driver's thinking time?

  • A). Poor brakes and tiredness
  • B). Alcohol and the weight of the lorry
  • C). Medical drugs and lack of sleep
  • D). The quality of the tires and the road conditions

6. What 2 factors could affect the driver's braking time?

  • A). Poor brakes and tiredness
  • B). Alcohol and the weight of the lorry
  • C). Medical drugs and lack of sleep
  • D). The quality of the tires and the road conditions

These questions are about a see-saw. When different children sit on the see-saw they find they have to move to different points to make the see-saw balance. What are the missing values needed to make the see saw balance?
Left Hand Side
Right Hand Side
 
Name
mass (kg)
distance from pivot (m)
Name
mass (kg)
distance from pivot (m)
7.
Abby
60
1.5
Charlie
90
8.
Borat
75
Elin
45
2
9.
Doris
2.1
Fred
57
1.4
10.
?
1.6
Goh
40
2.4

 

see_saw

11. Which of these letters correctly shows the centre of gravity of this shape?

CofG

A long wire is stretched using a large force. The table shows the length of the wire for different forces.

Force (N) Length (m)
100 10.0
200 10.8
300 11.6
400 12.4
500 13.2
600 14.5
700 16.0

 

 wire Weight

12. What is the extension of the wire when the first 100N is applied?
13. What was the original length of the wire?
14. At what length is the limit of proportionality reached?
15. Hookes law states that the
is proportional to the applied force.
16. What force would produce a length of 11.2 m?

17. Which of these does not show Hooke's Law properties?

  • A) Rubber bands
  • B) Metal Wires
  • C) Springs
  • D) Steel cables

18. Which of these is the best description for friction?

  • A) A loss of energy as an object falls through air
  • B) The ground pushing on a tyre
  • C) A force caused by the air pushing upwards
  • D) A force acting against motion