Physics (4th form) - Momentum + 3rd Law + Stopping Distance

Question 1

Braking distance

Answer 1

The amount of Time it takes between putting your foot down on the brakes and the car coming to a stop

Question 2

Thinking distance

Answer 2

The amount of time between a stimulus and your body doing an action

Question 3

Stopping distance.

Answer 3

The total time between the stimulus and the car coming to a stop- thinking distance + braking distance

Question 4

Newton’s third law

Answer 4

Every action has an equal opposite reaction- whoever two objects interact, the forces get exert on each other are equal and opposite

Question 5

Equation for momentum

Answer 5

Momentum (Kgm/s) = mass (kg) x Velocity (m/s)

P = M x V

Question 6

Things that may affect thinking distance

Answer 6

Things that may affect reaction time include:

• Alcohol
• Drugs
• Tiredness
• Distraction (eg. loud music, on phone etc.)

Question 7

Typical range of reaction times

Answer 7

Reaction times vary from person to person. On average it is 0.2-0.9 seconds

Question 8

Name experiments that we could use to find a reaction time

Answer 8

• ruler drop test

- tapping a key on a keyboard when a sound is played or a picture is shown.

Question 9

Name things that may increase braking distance

Answer 9

• bad road
• bad weather (eg. Black ice or heavy rain)
• poor condition of the brakes or tyres

Question 10

Dangers of large deceleration

Answer 10

The greater the speed of a Vehicle, the greater the braking force needed to stop it. Large deceleration may cause the brakes to overheat meaning the driver loses control.

Question 11

Law of conservation of momentum

Answer 11

The total momentum before an event is equal to the total momentum after the event