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 rolling friction as the truck tires sink into the gravel brings the truck safely to a halt. Suppose a gravel ramp slopes upward at 6.0° and the coefficient of rolling friction is 0.32. Part A Use work and energy to find the length of a ramp that will stop a 15,000 kg truck that enters the ramp at 35 m/s. Express your answer to two significant figures and include the appropriate units.

A crate with mass m = 33.3 kg being pushed up an incline that makes an angle φ = 22.7 degrees with horizontal. The pushing force is horizontal, with magnitude P, and the coefficient of kinetic friction between the crate and the incline is μ = 0.358. Consider the work done on the crate as it moves a distance d = 5.32 m at constant speed. a. What is work done by the pushing force, in joules?  b. What is the work done by friction, in joules?  c. What is the work done by gravity, in joules?  d. What is the net work, in joules?

Part A A horizontal spring with spring constant 140 N/m is compressed 17 cm and used to launch a 2.1 kg box across a frictionless, horizontal surface. After the box travels some distance, the surface becomes rough. The coefficient of Use work and energy to find how far the box slides across the rough surface before stopping. kinetic friction of the box on the surface is 0.15. Express your answer using two significant figures. ? cm = 1

a In the figure, a constant force Ễ of magnitude 85.0 N is applied to a 7.0 kg shoe box at angle = 54.0°, causing the box to move up a frictionless ramp at constant speed. How much work is done on the box by Fa when the box has moved through vertical distance h = 0.35 m? а Use correct number of significant digits. The tolerance is + 1 in the 3rd significant digit. Number i 42.02 ! Units J

A 79 kg bike racer climbs a 1400-m-long section of road that has a slope of 4.3° Part A By how much does his gravitational potential energy change during this climb? Express your answer with the appropriate units. AU = O μÅ Value Units ?

A 100 kg block is pulled at a constant speed of 5.5 m/s across a horizontal floor by an applied force of 137 N directed 37° above the horizontal. What is the rate at which the force does work on the block? W

(Figure 1) is the force-versus-position graph for a particle moving along the x-axis. Figure Fx (N) 4 2 0 -2 -4 1 2 3 -x (m) ▼ Part A Determine the work done on the particle during the interval 0-1 m. Express your answer with the appropriate units. Wo-1 = Units You have already submitted this answer. Enter a new answer. No credit lost. Try again. Submit Part B ΠΑ W1-2 = Submit Value Previous Answers Request Answer Determine the work done on the particle during the interval 1-2 m. Express your answer with the appropriate units. μA Value Units ? www Previous Answers Request Answer ? Units input for part B

Two tugboats pull a disabled supertanker. Each tug exerts a constant force of 1.2×106 N, one an angle 16° west of north and the other an angle 16° east of north, as they pull the tanker a distance 0.76 km toward the north. Part A What is the total work they do on the supertanker? Express your answer in joules. VE ΑΣΦ W = ?

A 20.0-kg child descends a slide 1.80 m high and reaches the bottom with a speed of 1.25 m/s . Part A How much thermal energy due to friction was generated in this process? Express your answer to three significant figures and include the appropriate units.

You are on vacation in San Francisco and decide to take a cable car to see the city. A 5800-kg cable car goes 460 m up a hill inclined 13° above the horizontal. The system is the car and Earth. Part A Determine the change in the total energy of the system when the car moves from the bottom to the top. Ignore friction. Express your answer with the appropriate units.