A 3.5 × 103

Question

kg car accelerates from rest at
the top of a driveway that is sloped at an angle of 16.9◦ with the horizontal. An average frictional force of 4.1×103 N impedes the car’s
motion so that the car’s speed at the bottom of the driveway is 4.2 m/s.
The acceleration of gravity is 9.81 m/s^2.
What is the length of the driveway?
Answer in units of m

Answer 1

the net acceleration is
___ g sin(16.9º) - (4.1×103 N / 3.5 × 103
kg)

divide the speed at the bottom by the acceleration to get the time for the trip

the average speed is (0 + 4.2) / 2

speed times time is distance (the length of the driveway)