science
posted by anonymous .
a car of mass 900 kg moves at 10 m/s. what is the braking force required to stop the car in a time of 5 seconds?

Find the required acceleration.
a = (VfVi)/t
where Vf = final velocity and Vi = initial velocity
You want final velocity to be 0.
a = (010)/5
a = 2 m/s/s
Now to find the force:
F = ma
F = 900*2
F = 1800N
The force required is 1800N applied opposite from the direction of motion.