Question

Определите,выполняет ли работу сила тяжести,действующая на баскетбольный мяч,который:лежит на земле;катится по полу спортивного зала;летит вверх;падает.Если выполняет,то какую- положительную или отрицательную?

Answer 1

Если мяч лежит А=0; катится по полу А=0; летит вверх А<0; падает А>0

Answer 2

Does the force of gravity acting on a basketball perform work in different scenarios?

The force of gravity acting on a basketball can perform work in different scenarios. Let's examine each scenario individually:

1. When the basketball is lying on the ground: In this case, the force of gravity is acting on the basketball, but it is not performing any work because the basketball is not moving. The work done by gravity is zero in this scenario.

2. When the basketball is rolling on the floor of a sports hall: In this scenario, the force of gravity is still acting on the basketball, but it is also experiencing a frictional force from the floor. The work done by gravity depends on the direction of motion. If the basketball is rolling downhill, gravity is doing positive work by providing the force that accelerates the basketball. If the basketball is rolling uphill, gravity is doing negative work, opposing the motion of the basketball.

3. When the basketball is flying upwards: In this scenario, the force of gravity is acting on the basketball, but it is not performing any work because the displacement of the basketball is perpendicular to the force of gravity. The work done by gravity is zero in this scenario.

4. When the basketball is falling: In this scenario, the force of gravity is acting on the basketball and is performing positive work. Gravity is providing the force that accelerates the basketball towards the ground, and as a result, work is being done by gravity.

To summarize, the force of gravity can perform positive work when the basketball is rolling downhill or falling, and it does not perform work when the basketball is lying on the ground or flying upwards.