Post a New Question

physics

posted by .

Truck brakes can fail if they get too hot. In some mountainous areas, ramps of loose gravel are constructed to stop runaway trucks that have lost their brakes. The combination of a slight upward slope and a large coefficient of friction in the gravel brings the truck safely to a halt.

Suppose a gravel ramp slopes upward at 4.70° and the coefficient of friction is 0.410. Find the length of a ramp that will stop a 14980.0 kg truck that enters the ramp at 37.0 m/s.

  • physics -

    The gravel will work efficiently if the brakes of the truck are at least working, even though they may not be in perfect condition.

    The kinetic energy, Ek of the truck on entering the ramp
    =(1/2)mv²

    Increase in potential energy, Ep, at the end of the ramp of length L
    =mgLsin(θ)

    Work done, W, against friction
    =μmgcos(θ)*L

    Equate energies and work done:
    Ek=Ep+W
    and solve for L.
    I get L=142 m. approximately.
    Check my work.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    A truck of mass 9212 kg moving at a speed of 73.2 mph has lost its brakes. Fortunately, the driver finds a runaway lane, a gravel-covered incline that uses friction to stop a truck in such a situation; see the figure. In this case, …
  2. Physics

    Two trucks having equal speeds hit their brakes at the same time, but truck has three times the acceleration as truck . Question:If truck B stops in time T, how long (in terms of T) will it take for truck A to stop?
  3. physics

    A semi-trailer is coasting downhill along a mountain highway when its brakes fail. The driver pulls onto a runaway truck ramp that is inclined at an angle of 17.0° above the horizontal. The semi-trailer coasts to a stop after traveling …
  4. Physics

    A semitrailer is coasting downhill along a mountain highway when its brakes fail. The driver pulls onto a runaway-truck ramp that is inclined at an angle of 10.0° above the horizontal. The semitrailer coasts to a stop after traveling …
  5. physics

    A semi-trailer is coasting downhill along a mountain highway when its brakes fail. The driver pulls onto a runaway truck ramp that is inclined at an angle of 19.0° above the horizontal. The semi-trailer coasts to a stop after traveling …
  6. Physics

    A 13,900 kg truck is moving at 23.5 m/s on a mountain road when the brakes are applied. The brakes FAIL!! Fortunately, the driver sees a deceleration (ouch!) ramp a short distance ahead. This is an incline used by out of control trucks …
  7. Gen physics

    A 13,900 kg truck is moving at 23.5 m/s on a mountain road when the brakes are applied. The brakes FAIL!! Fortunately, the driver sees a deceleration (ouch!) ramp a short distance ahead. This is an incline used by out of control trucks …
  8. general physics

    A 13,900 kg truck is moving at 23.5 m/s on a mountain road when the brakes are applied. The brakes FAIL!! Fortunately, the driver sees a deceleration (ouch!) ramp a short distance ahead. This is an incline used by out of control trucks …
  9. physics

    A semi-trailer is coasting downhill along a mountain highway when its brakes fail. The driver pulls onto a runaway truck ramp that is inclined at an angle of 13.0° above the horizontal. The semi-trailer coasts to a stop after traveling …
  10. physics

    A truck of mass 8912 kg moving at a speed of 66.7 mph has lost its brakes. Fortunately, the driver finds a runaway lane, a gravel-covered incline that uses friction to stop a truck in such a situation; see the figure. In this case, …

More Similar Questions

Post a New Question