A driver parks his car on a hill but accidently leaves it in neutral. The car starts from rest and accelerates down the 45 m long hill. It take the car 12.3 seconds to reach the bottom of the hill.

Question

a) What is the final velocity of the car at the bottom of the hill? (ANS: 7.3 m/s)

b) Once at the bottom of the hill, the car accelerates due to friction at 1.2 m/s2 [backward] along the level ground. How far will the car coast before stopping once it is off the hill? (ANS: 22.3 m)

***show steps please***

Answer 1

a. average velocity=distance/time=45/12.3 m/s
final velocity=2 x average velocity
= 90/12.3 m/s

b. vf^2=vi^2+2ad
0=(90/12.3)^2 + 2(-1.2)d
solve for d