science/math

posted by .

A car traveling at the speed of 30.0 m/sec encounters an emergency and comes to a complete stop. how much time will it take for the car to stop if its rate of deceleration is -4.0 m/sec

  • science/math -

    Using Calculus

    a = -4
    v = -4t + c
    when t=0 , v = 30
    30 = 0 + c
    v = -4t + 30

    s = -2t^2 + 30t + k
    when t = 0 , s = 0, so k = 0

    s = -2t^2 + 30t

    when the car stops, v = 0
    4t = 30
    t = 30/4 = 7.5 seconds

    when t = 7.5
    s = -2(7.5)^2 + 30(7.5) = 112.5 m

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    A car with good tires on a dry road can decelerate at about 5.0m/s/s when braking. If the car is traveling at 55miles/hour, how much time does it take the car to stop?
  2. physics, please help check

    A rocket car is traveling on a linear horizontal frictionless track when it suddenly runs out of fuel. The car has achieved a speed of 100 meters per second at the very moment the fuel is completely spent. The track then suddenly changes …
  3. physics

    A car comes to a stop for a stop sign in 4.6 seconds. If it was initially traveling at 27.5 m/s, how much space did it take for the car to stop?
  4. physics

    if a car goes from 10 m/s to a full stop,then its change in velocity is 10m/s.if it decelerates at a rate of 2.5 m/sec square,it will take 4 sec to stop.how far this car will travel when braking to a stop?
  5. physics

    if a car goes from 10 m/s to a full stop,then its change in velocity is 10m/s.if it decelerates at a rate of 2.5 m/sec square,it will take 4 sec to stop.how far this car will travel when braking to a stop?
  6. math

    a car is traveling at a speed of 30.0m/s encounters an emergency and comes to complete stop how much time will it take for the car to stop if it decelerates -4.o m/s^2
  7. Calculus1

    A car braked with constant deceleration of 16 ft/sec^2 takes 200 ft to come to a complete stop. How fast was the car traveling when the breaks were first applied?
  8. science

    am confused. don't know what formula to use for this problem. A car traveling at a speed of 30.0m/s encounters an emergency and comes to a complete stop. How much time will it take for the car to stop if it decelerates at -4.0m/s?
  9. Science/Math

    A car is travelling at a speed of 30.0m/s encounters an emergency and comes to a complete stop. How much time will it take for the car to stop at -4.0m/s^2
  10. physics

    In 5 seconds a car accelerate from 0 to 40 m/s. 20 sec after reaching 40m/s the car comes to a complete stop. if this deceleration takes 4 sec, how far has the traveled since its trip began?

More Similar Questions