Question

A motorcycle racer falls off their motorbike while travelling at 143 km/hr and skids in a straight line down the track. If the friction with the track decelerates the rider at a uniform rate of 3.8 m/s/s, how long (what time) would it take for the rider to come to a stop?

Answer 1

These last two are just like the one I answered. Come back with your work if you get stuck.

Answer 2

can you show the formula on how to figure this out?

Answer 3

change initial velocity to m/s
vf=vi+vi*t+1/2 a t^2
vf=0, vi=initial velocity
a=-3.8, so you solve for time t. It is a quadratic equation, I recommend put it in this form...
1/2 at^2+Vi*t-Vi=0 and solve