[Linear Motion]

Question 1

8. Constant Acceleration Equations

Answer 1

s u v a t equations. Acceleration is constant. Air resistance is assumed to be negligible. v = u + a t.
s = u t + 1⁄2 a t2.
s = 1⁄2 (u + v) t.
v2 =u2 +2as

Question 2

9. Uniform Gravitational Field

Answer 2

Gravitational field has a constant gravitational field strength, g. For example, g = 9.81 ms-2 or Nkg-1. Field lines are parallel. Objects have a weight equal to W = m g and acceleration due to gravity is g.

Question 3

10. Air Resistance

Answer 3

The drag or resistive force experienced by objects moving through air.

Question 4

11. Acceleration of Freefall

Answer 4

g. The rate of change of velocity of an object falling in a gravitational field. Measured in ms-2 or Nkg-1.

Question 5

12. Trapdoor and Electromagnet

Answer 5

Equipment used to measure acceleration of freefall using an electromagnet free fall apparatus with a timer and metre rule.

Question 6

13. Light Gates and Timer

Answer 6

A digital switch-type sensor most commonly used in timing experiments. The light gate has an IR transmitter and receiver that will detect an object passing through the ‘gate’. They can be used singly or in pairs to measure the time, speed, velocity and acceleration of the moving object.

Question 7

14. Reaction Time

Answer 7

Time taken by the driver to react / see the hazard and apply the brakes.

Question 8

15. Thinking Distance

Answer 8

Distance travelled by the car in the time taken by the driver to react / see the hazard and apply the brakes.

Question 9

16. Braking Distance

Answer 9

Distance travelled by the car from when the brakes are applied to when the car stops / comes to rest.

Question 10

17. Stopping Distance

Answer 10

Stopping Distance = Thinking Distance + Braking Distance.