Physics

posted by .

The speed limit in a school zone is 40 km/h. A driver traveling at this speed sees a child run into the road 23 m ahead of hs car. He applies the brakes, and the car decelerates at a uniform rate of 8.0m/s^2. if the driver's reaction time is .25s, will the car stop before hitting the child?

  • Physics -

    Using Vf = Vi + at we can calculate how long it will take the car to stop from 11.11 m/s. It will take 1.39s but the reaction time adds .25s so it the time it takes will be 1.64s to stop the car.
    Now use S = Vit + (1/2)at^2 to see if the car will stop before 23m.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    The speed limit in a school zone is 40.0 km/hr. A driver traveling at this speed sees a child run into the road 14 m ahead of the car. The driver applies the brakes and the car slows at a uniform rate of 8.3 m/s^2. If the driver's …
  2. physics

    The speed limit in a school zone is 38 km/h. A driver traveling at this speed sees a child run onto the road 16 m ahead of his car. He applies the brakes, and the car decelerates at a uniform rate of 8.5 m/s2. If the driver's reaction …
  3. physics

    The driver of the car traveling at a constant 25m/s sees a child suddenly run into the road. It takes the driver 0.45s to hit the brakes. As it slows, the car has a steady acceleration of 8.5m/s©ü. What the total distance the car …
  4. physics

    The driver of a car, traveling at a constant 25 m/s, sees a child suddenly run into the road. It takes the driver 0.45s to hit the brakes. As it slows, the car has a steady acceleration of 8.5 m/s^2. What's the total distance the car …
  5. Physics

    A car is traveling at 16.0 m/s, and the driver sees a traffic light turn red. After 0.500 s (the reaction time), the driver applies the brakes, and the car decelerates at 8.00 m/s2. What is the stopping distance of the car, as measured …
  6. Physics

    A car is traveling at 11.0 m/s, and the driver sees a traffic light turn red. After .59 s (the reaction time), the driver applies the brakes, and the car decelerates at 8 m/s^2. What is the stopping distance of the car, as measured …
  7. Physics

    A car is initially travelling at 30m/s, which is above the speed limit. The driver sees a speed limit trap ahead and applies the brakes for 5 seconds, causing the car to slow down by 2m/s every second while the brakes are on. How far …
  8. physics

    A car is initially travelling at 30 m/s, which is above the speed limit. The driver sees a speed limit trap ahead and applies the brakes for 5 seconds, causing the car to slow down by 2m/s every second while the brakes are on. –How …
  9. Physics

    A car is traveling at 50km/h. The driver sees a child run out into the road 5m ahead. She applies the breaks and the car stops in 5s. The driver's thinking time is 1.5s. a. Will the car stop in time?
  10. Science (physics)

    The driver of a car travelling along a straight road with a speed of 72km/hour observe a signboard which give a speed limit to be 54 km/hour. The sign board is 70m ahead when the driver applies the break calculate the acceleration …

More Similar Questions