Question

During normal driving, some drivers use the trolley (hand valve) before the brake in order to prevent trailer skids. Which of the following statements is true?

1) Using the trolley before the brake helps to prevent trailer skids
2) Using the trolley before the brake has no effect on preventing trailer skids
3) Using the trolley before the brake increases the risk of trailer skids
4) Using the trolley before the brake is only necessary in certain driving conditions

Answer 1

Using the trolley (hand valve) before the brake can help prevent trailer skids during normal driving by controlling the speed of the truck.

Step-by-step explanation:

Using the trolley (hand valve) before the brake can help prevent trailer skids during normal driving.

When a truck is traveling downhill, the brakes convert gravitational potential energy into increased internal energy of the brake material, preventing the energy from being converted into kinetic energy. However, the mass of the truck is large compared to the brake material, causing the temperature to increase rapidly. Using the trolley before the brake can control the speed and prevent trailer skids by gradually reducing the speed of the truck.