When you kick a ball on the surface of the Earth, it eventually stops due to the presence of several factors, including friction, air resistance, and the force of gravity. These factors counteract the ball's motion and cause it to come to a halt.
Friction: The ball experiences friction with the ground, which opposes its motion. Friction converts the ball's kinetic energy into heat energy and gradually slows it down until it stops. The amount of friction depends on the surface the ball is rolling on and the characteristics of the ball itself.
Air Resistance: If the ball is moving through the air, it encounters air resistance. Air molecules push against the ball in the opposite direction of its motion, acting as a resistance force. Air resistance further slows down the ball's motion, especially if it is moving at higher speeds.
Gravity: Gravity is a force that pulls objects towards the center of the Earth. In the case of a ball rolling on the Earth's surface, gravity acts vertically downward, causing the ball to experience a downward force. This force contributes to the ball's deceleration, gradually reducing its speed until it comes to a stop.
The Earth's Shape: The shape of the Earth being a sphere does not cause the ball to roll down to the "bottom" as you suggest. Gravity pulls objects towards the center of the Earth, so when you are standing on the surface, you are already at the "bottom" relative to your local environment. Gravity acts perpendicularly to the tangent plane of the Earth's surface, making objects fall towards the ground rather than rolling off the surface.
In summary, the ball stops rolling due to a combination of factors including friction, air resistance, and gravity. These forces act against the ball's motion, gradually reducing its speed until it comes to a halt. The shape of the Earth being a sphere is not a factor in the ball's stopping motion; rather, it is the presence of these other forces that influence its movement.