physics

A car moving at 50 km/h skids 15 m with locked brakes. Show that a car moving at 150 km/h will skid 135 m with locked brakes. (Hint: The force doing work during the skidding is the same for both speeds. Use the work–energy theorem.)

  1. 👍 0
  2. 👎 0
  3. 👁 990
  1. work = force * distance
    = F d
    F the same for both

    work done = kinetic energy lost
    = .5 m v^2
    same m
    V2 = 3 V1
    so
    V2^2 = 9 V1^2
    so work done at 50 = (1/2)m V1^2 = F d1
    and at 150 = (1/2) m (9 V1 ^2) = F d2
    so
    d2/d1 = 9
    9 * 15 = 135

    1. 👍 0
    2. 👎 0
    posted by Damon

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physict

    This question is similar to some on driver's-license exams: A car moving at 50 km/h skids 15 m with locked brakes. Show that with locked brakes at 150 km/h the car will skid 135 m.

    asked by Jaime on April 8, 2014
  2. PHSC

    Hello, i need help. This is Work-Energy Theorum A car moving at 50km/hr skids 15m with locked brakes. How far will the car skid (with locked brakes if the car moves at 100km/hr assume that the mass of the car is 500kg

    asked by latrice on July 20, 2011
  3. Physical science

    A car moving at 50km/hr skids 15m with locked brakes. How far will the car skid (with locked brakes if the car moves at 100km/hr assume that the mass of the car is 500kg

    asked by latrice on July 20, 2011
  4. physics

    A car moving at 50 km/h skids 15m with locked brakes. show with locke brakes at 150 km/m the car will skid 135?

    asked by jeremy steadman on January 5, 2014
  5. physics

    This question is typical on some driver’s license exams: A car moving at 40 km/h skids 12 m with locked brakes. How far will the car skid with locked brakes at 80 km/h? Answer in units of m

    asked by LYNN on September 27, 2012
  6. physics

    This question is typical on some driver's license exams: A car moving at 50km/hr skids 15m with locked brakes.How far will the car skid with locked brakes at 120 km/h?

    asked by jim on February 27, 2012
  7. physics

    disregard the previous I did not include the first part This question is typical on some driver's license exams: A car moving at 50 km skids 15 m with locked brakes.How far will the car skid with locked brakes at 120 km/h?

    asked by Mrs G on March 3, 2012
  8. Physics

    A car moving at 43 km/h skids 16 m with locked brakes. How far will the car skid with locked brakes at 129 km/h?

    asked by Andrea on November 25, 2012
  9. Physics

    A car moving at 60 km/h skids 13 m with locked brakes. How far will the car skid with locked brakes at 180 km/h?

    asked by JESS on January 9, 2017
  10. physics

    QA: This question is typical on some driver’s license exams: A car moving at 40 km/h skids 12 m with locked brakes. How far will the car skid with locked brakes at 80 km/h? Answer in units of m QB:A cheerleader lifts his 62.2 kg

    asked by LYNN on September 27, 2012

More Similar Questions