physics

A car starts from rest and travels for 6.0 s with a uniform acceleration of +2.4 m/s2. The driver then applies the brakes, causing a uniform acceleration of −1.0 m/s2. If the brakes are applied for 3.0 s, determine each of the following.
(a) How fast is the car going at the end of the braking period?
(b) How far has the car gone?

  1. 👍 0
  2. 👎 0
  3. 👁 1,488
  1. (a) After 6.0 s, the car's velocity is
    a*t = 2.4 * 6 = 14.4 m/s and it will have travelled
    X = (a/2) t^2 = 86.4 m.
    Three seconds of braking at -1.0 m/s^2 then reduces the velocity, by 3.0 m/s, from
    14.4 to 11.4 m/s.
    (b) Additional distance travelled while braking
    = (avg. speed durng interval)*3.0 s
    = 12.9 * 3 = 38.7 m
    Add 38.7 m to 86.4 m for the total distance travelled during the 9.0 seconds.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics, dynamics

    Car A starts from rest at t = 0 and travels along a straight road with a constant acceleration of 2 m/s2 until it reaches a speed of 27 m/s. Afterwards it maintains this speed. Also, when t = 0, car B located 2000 m down the road

  2. physics

    A car starts from rest and travels for 5.0 s with a uniform acceleration of +2.5 m/s2. The driver then applies the brakes, causing a uniform negative acceleration of -3.0 m/s2. If the brakes are applied for 2.0 s, how fast is the

  3. physics

    a car starts from rest , attains a velocity of 36kmph with an acceleration of 0.2m/s^2 travels 9km with this uniform velocity and then comes to halt with a uniform acceleration of 0.1m/s^2 find the total time of travel of the car.

  4. physics

    A test car starts out from rest on a horizontal circular track of 80m radius and increases it's speed at a uniform rate to reach 27.78 m/s in 10s. Find the magnitude of the total acceleration of the car 8s after the start. Ok so I

  1. physics

    a particle starts moving from rest with uniform acceleration . it travels a distance y in the next 2 sec

  2. physics

    A 75 kg man stands on a spring scale in an elevator. Starting from rest, the elevator ascends, attaining its maximum speed of 1.6 m/s in 1.1 s. It travels with this constant speed for the next 7.2 s, undergoes a uniform negative

  3. physics

    a car has a mass of 820 kg. It starts from rest and travels 41 m in 3.0s. What is the net force applied to the car?

  4. physics

    A car starts from rest and travels for t1 seconds with a uniform acceleration a1. The driver then applies the brakes, causing a uniform acceleration a2. If the brakes are applied for t2 seconds, determine the following. Answers

  1. Physics

    A car starts from rest accelerate uniformly until it reaches a velocity of 30m/s after 5s.it traves with uniform velocity for 15s and is being brought to rest in 10 with a uniform retardation.dEtermine the following (a) the

  2. 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

  3. physics

    A car starts from rest and travels for 6.0 s with a uniform acceleration of +1.2 m/s2. The driver then applies the brakes, causing a uniform acceleration of -1.8 m/s2. The breaks are applied for 1.70 s. (a) How fast is the car

  4. physics

    A car starts from rest and travels for 5.3 s with a uniform acceleration of +1.2 m/s2. The driver then applies the brakes, causing a uniform acceleration of -2.3 m/s2. The breaks are applied for 1.60 s. How fast is the car going

You can view more similar questions or ask a new question.