A 2500‐kg vehicle traveling at 25 m/s can be stopped by gently applying the breaks for 20 seconds. What is the average force supplied by the breaks to stop the vehicle?

Answer 1

Write "brake", and "braking" when stopping a car.

m=2500 kg
vi=25 m/s
vf=0
t=20 s

vf=vi+aΔt
0=25+a(20)
solve to get
a=-25/20=-5/4=-1.25 m/s²

Use Newton's second law to get force
force, f = ma
=2500 (-1.25) N
=-3125 N

Ignore the negative sign if understood to be braking force.