Question

2. A semi tractor-trailer truck enters a runaway truck ramp at a ramp design speed of 90 MPH. The loaded truck weighs 64,400 lbs. The truck’s brakes have failed, and the ramp must dissipate all of the energy for the truck to come to a halt. The ramp is inclined with a slope of 5% (1 ft of vertical rise for every 20 ft of horizontal run). The ramp bed is filled with sand. a. Take the entrance of the ramp as the zero level for gravitational potential energy. With how much energy does the truck enter the ramp? (10 pts) After the truck stops, the crew sent to refresh the ramp takes measurements. Based on the tire tracks, the truck traveled 530 feet along the ramp before coming to a stop. b. What is the truck’s elevation above the level of the ramp entrance? How much energy, and what percentage of the total energy to be dissipated, was taken up in the change in elevation? (10 pts) c. How much energy and what percentage of the total energy to be dissipated was taken up by the resistance to motion from the sand in the ramp? What is the average force and the average acceleration that acted on the truck due to the sand as it rolled up the ramp? (10 pts

Answer 1