Question

Футбольный мяч находится на футбольном поле. Одинаковая ли сила тяжести действует на мяч в следующие моменты:а) когда он находится в руках у вратаря б) когда вратарь отбивает мяч и он летит горизонтальнов) когда мяч катится по футбольному полюг) когда он летит вверхд) когда он летит внизОдинаков ли вес мяча в эти моменты?

Answer 1

Сила тяжести одинакова, поскольку она определяется гравитационным полем Земли, которое поле у поверхности вплоть до расстояний, сравнимых с радиусом планеты, можно считать однородным.
Вес не одинаков. В частности, когда мяч летит горизонтально, вниз, вверх (да хоть наискосок) веса НЕТ вообще, поскольку в "эти моменты" отсутствует опора, на которую мяч мог бы давить под действием силы тяжести.

Answer 2

The Force of Gravity on a Football in Different Scenarios

When considering the force of gravity acting on a football in different scenarios, it is important to understand that the force of gravity is constant and always acts on the football. However, the effect of gravity may be influenced by other factors such as air resistance, velocity, and the surface on which the ball is located.

a) When the ball is in the hands of the goalkeeper: When the football is in the hands of the goalkeeper, the force of gravity still acts on the ball. However, the goalkeeper's grip on the ball counteracts the force of gravity, preventing the ball from falling to the ground. The weight of the ball remains the same, but the goalkeeper's grip provides an opposing force to gravity, resulting in the ball remaining stationary in the goalkeeper's hands.

b) When the goalkeeper kicks the ball and it flies horizontally: When the goalkeeper kicks the ball and it flies horizontally, the force of gravity continues to act on the ball. However, the horizontal motion of the ball counteracts the vertical pull of gravity, resulting in the ball maintaining its horizontal trajectory. The weight of the ball remains the same, but the horizontal motion of the ball balances the vertical force of gravity, allowing the ball to travel horizontally.

c) When the ball rolls on the football field: When the ball rolls on the football field, the force of gravity continues to act on the ball. The weight of the ball remains the same, and gravity pulls the ball downward. However, the friction between the ball and the ground opposes the downward pull of gravity, allowing the ball to roll along the surface of the field. The force of gravity and the opposing force of friction work together to determine the speed and direction of the rolling ball.

d) When the ball is flying upward: When the ball is flying upward, the force of gravity acts on the ball in the opposite direction, pulling it downward. As the ball ascends, its velocity decreases due to the opposing force of gravity. The weight of the ball remains the same, but the upward motion of the ball is gradually slowed down by the downward pull of gravity until it reaches its maximum height and starts descending.

e) When the ball is falling downward: When the ball is falling downward, the force of gravity acts on the ball, accelerating it toward the ground. The weight of the ball remains the same, and gravity pulls the ball downward, increasing its velocity as it falls.

In summary, the force of gravity is always acting on the football in all the mentioned scenarios. However, the effect of gravity may be influenced by other factors such as the grip of the goalkeeper, the horizontal or vertical motion of the ball, and the opposing forces like friction and air resistance. The weight of the ball remains the same, but the balance between the force of gravity and other forces determines the ball's behavior in each scenario.