PHYSICS - reaction time and stopping distances

p8 global challenges

km/h --→ metres/hour

x 1000

km/h --→ m/s

(x1000) /3600

typical speed of car

31m/s

typical speed of walking

1\.4m/s

typical speed of running

3\.3m/s

typical speed of wind

6m/s

typical speed of sound

330m/s

what is an accelerometer?

measures acceleration in terms of g (gravity)

acceleration of gravity?

10m/s2

how can we measure human reaction times?

ruler drop test

typical human reaction time?

0\.25 secs

conservation of momentum?

momentum before collision = sum of momentum after collision.

units of momentum?

kgm/s

what contributes to the stopping distance of a vehicle?

* braking distance
* thinking distance

factors that affect thinking distance?

* distractions
* tiredness
* drugs/alcohol

factors affecting braking distance

* road conditions
* condition of car
* speed of car