# AP Physics

posted by .

A car slows down from 18 m/s to rest in a distance of 91 m. What was its acceleration, assumed constant?

• AP Physics -

(Vf)^2 = Vo^2 + 2ad = 0,
(18)^2 + 2a*91 = 0,
324 + 182a = 0,
182a = -324,
a = -1.78m/s^2.

• AP Physics -

In coming to a stop, a car leaves skid marks 93 m long on the highway. Assuming a deceleration of 7.50 m/s2, estimate the speed of the car just before braking.

## Similar Questions

1. ### Physics

A car is traveling along a straight road at a velocity of +36.0 m/s when its engine cuts out. For the next ten seconds, the car slows down, and its average acceleration is 1. For the next five seconds, the car slows down further, and …
2. ### Physics B

A car slows down from 23 m/s to rest in a distance of 85m. What is its constant acceleration?
3. ### Physics

As soon as a traffic light turns green, a car speeds up from rest to 50.0 mi/h with a constant acceleration of 8.10 mi/h·s. In the adjoining bike lane, a cyclist speeds up from rest to 20.0 mi/h with a constant acceleration of 13.0 …
4. ### physics

Two cars cover the same distance in a straight line. Car A covers the distance at a constant velocity. Car B starts from rest and maintains a constant acceleration. Both cars cover a distance of 487 m in 216 s. Assume that they are …
5. ### physics

A car initially traveling at 26 m/s hits the brakes, generating a constant acceleration of -2 m/s2. Under this acceleration, the car comes to a rest. If the tires have radii of 0.33 m, how many revolutions does each tire make as the …
6. ### physics

A car slows down from 40 km/hr to rest in a distance of 72 m. What was its acceleration
7. ### Physics

As soon as a traffic light turns green, a car speeds up from rest to 45.0 mi/h with constant acceleration 8.50 mi/h/s. In the adjoining bike lane, a cyclist speeds up from rest to 15.0 mi/h with constant acceleration 12.50 mi/h/s. …
8. ### Physics

Two cars cover the same distance in a straight line. Car A covers the distance at a constant velocity. Car B starts from rest and maintains a constant acceleration. Both cars cover a distance of 515 m in 229 s. Assume that they are …
9. ### Physics

A car is braked so that it slows down with uniform retardation from 15 m/s to 7 m/s while it travels a distance of 88 m. If the car continues to slow down at the same rate, after what further distance will it be brought to rest?
10. ### phy211

A car accelerates from rest at 2.0 m/s2 for 20 s. The speed then remains constant for 20 s, after which the car slows down with an acceleration of 3 m/s2 until the car stops. What is the total distance traveled?

More Similar Questions