Question

A 1370-kg car is skidding to a stop along a horizontal surface. The car decelerates from 27.6 m/s to a rest position in 3.15 seconds. What is the frictional force that the skidding car experiences?

Answer 1

average velocity=27.6/2 m/s
distance=avgvel*time figure that.

vf^2=vi^2+2ad
but a= frictionforce/mass

solve for frictional force.