# Need help on a question i need review for a quiz

1. Feb 26, 2006

### albaboi123

i have this question that i couldn't get but it's on this quiz i have tommorow.

A 600-kg jet car accelerates from rest under the force of its jet engine.
After travelling 1.00 km in 21.0s, the jet engine shuts off and the jet car eventually comes to a rest at 1.4 km further down the track, stopped by the frictional force of the ground. Calculate the force due to the jet engine, and the constant frictional force applied while the car is in motion.

2. Feb 26, 2006

### topsquark

(Jet) You know how far the car has gone (from rest) in 21 s and you know it has done so with a constant acceleration. Can you think of a Kinematics relation between x, t, and a?

(Friction) Again you can figure the constant acceleration, so you can figure the net force on the car. What is causing this net force?

-Dan

3. Feb 26, 2006

### topsquark

(Jet) You know how far the car has gone (from rest) in 21 s and you know it has done so with a constant acceleration. Can you think of a Kinematics relation between x, t, and a?

(Friction) Again you can figure the constant acceleration (Hint: How fast is the car moving at 21 s?), so you can figure the net force on the car. What is causing this net force?

-Dan