Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Bill and his car (m= 2,000kg) are moving at a constant velocity of 30m/s when he

ID: 1495845 • Letter: B

Question

Bill and his car (m= 2,000kg) are moving at a constant velocity of 30m/s when he has to slam on the brakes and comes to a stop using a force of friction of 18,000 N.
A. What is the work done by friction to stop the car?
B. What distance did it take to stop the car from when Bill applies the brakes until he stopped? Bill and his car (m= 2,000kg) are moving at a constant velocity of 30m/s when he has to slam on the brakes and comes to a stop using a force of friction of 18,000 N.
A. What is the work done by friction to stop the car?
B. What distance did it take to stop the car from when Bill applies the brakes until he stopped?
A. What is the work done by friction to stop the car?
B. What distance did it take to stop the car from when Bill applies the brakes until he stopped?

Explanation / Answer

A) work by friction = - initial kinetic energy = - 0.5 x 2000 x (30)2 = 900000 J = 0.9 MJ

B) 900000 = 18000 x d => d = 50 m