Question

Человек толкает мяч с начальной скоростью 20 м/с вертикально вверх. Рассчитать работу и мощность силы тяжести на участке подъёма мяча. Какую работу совершила силы тяжести, действующая на мяч на второй секунде полёта.

Answer 1

Я решил на листочках....

Answer 2

Calculation of Work and Power of Gravity

To calculate the work and power of the force of gravity on the ball during its upward motion, we need to consider the initial velocity of the ball and the time at which we want to calculate the work.

Given: - Initial velocity of the ball: 20 m/s (vertically upward) - Time at which we want to calculate the work: 2 seconds

To calculate the work done by the force of gravity, we need to determine the change in height of the ball during the given time interval. Since the ball is moving vertically upward, the work done by the force of gravity will be negative, as gravity acts in the opposite direction to the motion.

The work done by the force of gravity can be calculated using the formula:

Work = Force x Distance

In this case, the force of gravity is equal to the weight of the ball, which can be calculated using the formula:

Weight = mass x acceleration due to gravity

The acceleration due to gravity is approximately 9.8 m/s^2.

To calculate the distance traveled by the ball, we can use the formula for vertical motion:

Distance = Initial velocity x time + (1/2) x acceleration x time^2

Substituting the given values into the formulas, we can calculate the work done by the force of gravity and the power of the force of gravity.

Calculation:

1. Calculate the weight of the ball: - Weight = mass x acceleration due to gravity - Since the mass of the ball is not given, we cannot calculate the weight directly.

2. Calculate the distance traveled by the ball: - Distance = Initial velocity x time + (1/2) x acceleration x time^2 - Distance = 20 m/s x 2 s + (1/2) x 9.8 m/s^2 x (2 s)^2

3. Calculate the work done by the force of gravity: - Work = Force x Distance - Since we don't have the weight of the ball, we cannot calculate the work directly.

4. Calculate the power of the force of gravity: - Power = Work / Time - Since we don't have the work done by the force of gravity, we cannot calculate the power directly.

Unfortunately, without the mass of the ball, we cannot calculate the work and power of the force of gravity on the ball during its upward motion. Please provide the mass of the ball so that we can assist you further with the calculations.