Chapter 3, Motion

Question 1

What is the area under a velocity-time graph?

Answer 1

Displacement (not distance!)

Question 2

What are thinking distance, breaking distance and stopping distance?

Answer 2

Thinking - The time from seeing the obstacle and applying the breaks
Breaking - The time from applying the breaks to coming to a complete stop
Stopping - The time from noticing the obstacle to coming to a complete stop

Question 3

What is the equation for thinking distance?

Answer 3

Thinking distance = speed x reaction time

Question 4

Give the two main practical ways of finding the speed of gravity in a lab

Answer 4

Using electromagnets and a timer
Using light gates

Question 5

What does the gradient of a displacement-time curve look like when an object is decelerating?

Answer 5

It is curving downwards

Question 6

How do you get velocity from a displacement time graph?

Answer 6

Find the gradient. Remember v is the differential of s and a is the differential of v

Question 7

What 4 things can affect thinking distance?

Answer 7

Tiredness
Alcohol/drugs
Illness
Distractions such as children

Question 8

What 3 things can affect breaking distance?

Answer 8

Bad brakes so reduces friction
Wet or icy roads (anything reducing the tyres friction with the road)
The weight of the car (a lighter car has less momentum)