Stopping Distances And Reaction Times Flashcards Preview

Physics 1 - Motion, Forces And Conservation Of Energy > Stopping Distances And Reaction Times > Flashcards

Flashcards in Stopping Distances And Reaction Times Deck (16)
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what is the stopping distance of a vehicle

the distance covered between the driver first spotting the hazard and the car coming to a complete stop


what makes up the stopping distance of a vehicle

- the thinking distance
- and the braking distance


what is the thinking distance

- the distance the car travels in the driver's reaction time
- time between noticing the hazard and pressing the brakes


what are the two factors that impact thinking distance

- your reaction time (could be increased by tiredness, alcohol, drug or distractions)
- your speed (the faster you are going, the further you will travel during your reaction time)


what is the braking distance

the distance taken to stop the car once the brakes have been applied


what are the four factors that impact braking distance

- your speed (the faster you are going, the longer it takes to stop)
- the mass of the car (a car full of luggage and people wont stop as quickly as an empty car)
- the condition of the brakes (worn or faulty brakes wont be able to brake with as much force)
- friction between tyres and the road (more likely to skid if road is icy, wet or dirty, and the tyres are bald)


what is the minimum depth a tyre must have in order to be safe on the road



what is the process of the ruler test

- sit with arm resting on the edge of a table
- get someone to hold a ruler so it hangs between your thumb and forefinger lined up at 0
- person holding ruler drops it without any warning
- close thumb and forefinger to try to catch ruler as quickly as possible
- measurement on the ruler at the point where it was caught
- is how far the ruler dropped in the time it took you to react


what are the two ways to measure reaction time

- use a computer based test
- or do the ruler drop test


why should someone place their arm flat on the edge of a table when doing the ruler drop test

to prevent them from moving their arm during the test


what does a longer distance regarding where you caught the ruler on the ruler drop test indicate

a longer reaction time


why may you need a third person in the ruler drop test

to be at eye level with the ruler and check if its lined up


what can you use to calculate the reaction time of the student catching the ruler and why

- the acceleration equation, (v -u) / t
- because the acceleration is constant and equal to gravity, 10m/s^2


what should you do to get a more accurate calculation in the ruler drop test

- repeat the drops many times
- and get an average of the distance the ruler fell


how would you make sure the ruler drop test if a fair test

- keep the variables you arent testing the same every time
- like use the same ruler for every drop and have the same person catching the ruler every time


what is the typical reaction time of an alert driver

about 1 second