Science

posted by .

Assume you are speeding down the freeway at 75 mph. The car weighs 1500 kg and the effective force of the brakes is 14400 N. The car in front of you suddenly slows down, it takes 3 seconds for the car to do so. Your initial velocity was 33.53 and your final velocity is 0. If your reaction time is 1.6 seconds, how long would it take to slow down? In meters and seconds.

  • Science -

    F = ma, so a = -144/15 = -9.6 m/s^2
    75 mi/hr = 33.53 m/s

    v = Vo + at = 33.53 - 9.6t
    v=0 at t=3.49

    So, it will take 1.6 + 3.49 = 5.09 seconds to stop

    No deceleration occurs during the first 1.6 seconds, so the distance is

    s = 33.53*5.09 - 4.9*3.49^2 = 110.99 m

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    You are driving at the speed of 33.4 m/s (74.7296 mph) when suddenly the car in front of you (previously traveling at the same speed) brakes. Considering an average human reaction, you press your brakes 0.484 s later. Assume that the …
  2. Physics

    You are driving at the speed of 33.4 m/s (74.7296 mph) when suddenly the car in front of you (previously traveling at the same speed) brakes. Considering an average human reaction, you press your brakes 0.484 s later. Assume that the …
  3. Physics

    A car is moving down a street at 67 km/h. A child suddenly runs into the street. If it takes the driver 1.26 s to react and apply the brakes, how many meters will the car have moved before it begins to slow down?
  4. Physics

    A car is going 18.3 m/s down a road. At time t=0s, a squirrel runs in front of the car 36 meters away. It takes the driver t=0.67s to slam on the brakes, but after that , the brakes offer a frictional force F(fr)=21000N. Her car masses …
  5. science

    Ann is driving down a street at 50 km/h. suddenly a child runs into the street. if it takes ann .75 seconds to react and apply the brakes. how many meters will ann have moved before she begins to slow down?
  6. science

    1. A car slows down from 23 m/s to 14 m/s over a time period of 3 seconds. The car’s mass is 1330 kg. What is the car’s acceleration, momentum, and force.
  7. physics

    You are driving at the speed of 34.3 m/s (76.7433 mph) when suddenly the car in front of you (previously traveling at the same speed) brakes. Considering an average human reaction, you press the brakes 0.429 s later. Assume that the …
  8. Physics Urgent!

    1.You are driving at the speed of 28.7 m/s (64.2138 mph) when suddenly the car in front of you (previously traveling at the same speed) brakes. Considering an average human reaction, you press the brakes 0.427 s later. Assume that …
  9. Science, Physics

    Assume you are speeding down the freeway at 75 mph. The car weighs 1500 kg and the effective force of the brakes is 14400 N. The car in front of you suddenly slows down, it takes 3 seconds for the car to do so. Your initial velocity …
  10. Physical Science

    Determine how long it will take given the scenario below (in time and in distance) to react to the car in front of you. Assume that the car in front of you takes 3 seconds to change speeds. Reaction time 1.6 seconds Speed: 75 mph Initial …

More Similar Questions