posted by .

A car starts from rest and accelerates uniformaly at the rate of 0.98m/s in 1hr.what is its final velocity?
A car starts from rest and reaches a velocity of 40m/s in 1minutes..(a)what is its acceleration?(b) If its acceleration remains constant,what will its velocity be in 15 minutes?
The brakes of a certain car can produce an acceleration of 6m/s2.(a)how long does it take the car to come to a stop from a velocity of 30m/s?(b) how far does the car travel during the time the brakes are applied?
A train is uniformly decelerated at 2.5 m/s2 during a 2s far does it travel before coming to a full stop?
A cyclist travelling uniformly at 30m/s sees a post 300m away and suddenly applies his brakes.If the bike stops in 4.8s,determine whether the cyclist hits the post.
A boy increases speed from 1.2m/s to 2.4m/s in 6s,how far does the boy travel?

  • physics -

    1 hr = 3600s.

    Vf = Vo + at,
    Vf = 0 + 0.98*3600 = 3528m/s.

    a. a = (Vf - Vo) / t,
    a = (40 - 0) / 60s = 0.67m/s^2.

    b. t = 15 min. * 60s/min = 900s.
    Vf = Vo + at,
    Vf = = 0 + 0.667 * 900 = 600m/s.

    a. t = (Vf - Vo) / a,
    t = (0 - 30) / -6 = 5s.

    b. d = (Vf^2 - Vo^2) / 2a,
    d = (0 - (30)^2) / -12 = 75m.

    Vf = Vo + at,
    Vo = Vf - at,
    Vo = 0 - (-2.5)*2 = 5m/s.

    d = (Vf^2 - Vo^2) / 2a,
    d = (0 - (5)^2) / -5 = 5m.

  • physics -

    Correction: Disregard the 1st 3 lines,
    and start at "a".

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    A racing car reaches a speed of 40 m/s. At this instant, it begins a uniform negative acceleration, using a parachute and a braking system, and comes to rest 5.0 s. (a)Determine the acceleration of the car. Work: 40m/s x 5s = 200m …
  2. Physics

    A car starts from rest and accelerates at 5 m/s^2 for 4 s, then maintains that velocity for 3 seconds, then decelerates at the rate of 2m/s^2 for 3 seconds. a) what is the final speed of the car?
  3. Physics (12)

    A car and train move together along parallel paths at 25 m/s [W]. The car then undergoes a uniform acceleration of 2.5m/s^2 [E] because of a red light and comes to rest. It remains at rest for 45s, then accelerates back to a velocity …
  4. physics

    A car starts from rest and reaches a velocity of 8 m/s in 4 seconds. a) What is its acceleration?
  5. Physics

    An object starts from rest an under a constant acceleration has traveled a displacement of 30.5 meters when it reaches a certain final velocity. The same object starts from rest, but has an acceleration which is a factor of 3.3 times …
  6. Physics

    A car starts from rest and accelerates at a rate of 1 m/s^2 until it reaches a velocity of 7 m/s. It then travels at a constant velocity for the next 15 seconds. The driver then applies the brake, bringing the car to stop. The brakes …
  7. 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 …
  8. physics

    Car a starts from rest and speeds up with constant accelleration until it reaches its max speed. Car b starts from rest, at the moment car a is at max speed, and speeds up with constant acceleration. How much time elapses between when …
  9. AP Physics

    A drag racer starts from rest and accelerates uniformly for 5s covering a distance of 120 m. a. what is the car's acceleration?
  10. physics

    a car starts from rest it reaches a velocity of 12 m/s in 6 second. a. what is its acceleration ?

More Similar Questions