# 4.5.4.3.1

Stopping distance and reaction time Wadebridge spec

# Resource sheet

Ruler Drop Experiment

Exam questions

# Video

Stopping Distances.mp4

## Stopping distances explained

Euro NCAP Crash Test of Ford Focus.mp4

# Practical / DEMO

### Practical

DEMO:

• Skateboard x2
• Fire Extinguisher (CO2)
• 2 x Alcohol (Ethanol) Rocket PDF Risk
• no bottle cap vs special bottle cap
• Methane rocket PDF Risk

• Alcohol first explain about the speed of exhaust- speed it up using a special nozzle. Then move onto methane rocket (hotter reaction)

Different Stations :

• Balloon fire down a string
• Two magnets repelling each other
• A spring toy (jumps into air)
• A boat in bowl of water - students push down and feel the force back)
• Picture of fire extingusher (BELOW)
• Picture of a gun (recoil)
• Picture of a canoe

### Safety

Safety procedures for methane and alcohol.

Warn students of loud noises

Studnets to stand behind the ignotion

Stopping distance and reaction time Wadebridge spec

## Content - WADEBRIDGE SpLIT SPEC

The stopping distance of a vehicle is the sum of the distance the vehicle travels during the driver’s reaction time (thinking distance) and the distance it travels under the braking force (braking distance). For a given braking force the greater the speed of the vehicle, the greater the stopping distance.

(Physics only) Students should be able to estimate how the distance for a vehicle to make an emergency stop varies over a range of speeds typical for that vehicle.

(Physics only) Students will be required to interpret graphs relating speed to stopping distance for a range of vehicles.

Reaction times vary from person to person. Typical values range from 0.2 s to 0.9 s.

A driver’s reaction time can be affected by tiredness, drugs and alcohol. Distractions may also affect a driver’s ability to react.

Students should be able to:

• explain methods used to measure human reaction times and recall typical results

• interpret and evaluate measurements from simple methods to measure the different reaction times of students

• evaluate the effect of various factors on thinking distance based on given data.