Question

Приведи примеры ситуаций,когда сила трения покое выполняет работу. Помогите 8 класс физика

Answer 1

1) человек по канату поднимается вверх
A=Fтр*h=m*g*h

2) машина едет  вверх по уклону
А=Fтр*S

Answer 2

Situations Where Friction Performs Work

Friction can perform work in various situations, such as:

1. Braking of a Car: - When a car applies brakes to stop, the friction between the brake pads and the wheels converts kinetic energy into thermal energy, thus performing work.

2. Rubbing Hands Together: - When you rub your hands together, the friction between them generates heat, which is a form of work being done against the force of friction.

3. Walking: - When you walk, the force of friction between your shoes and the ground allows you to move forward by providing the necessary traction.

4. Slowing Down of a Moving Object: - Friction between the moving object and the surface it's moving on can slow down the object, thus performing work against its motion.

In each of these examples, the force of friction is performing work by converting mechanical energy into thermal energy or by enabling motion.

I hope these examples help illustrate how friction can perform work! If you have any more questions or need further clarification, feel free to ask.