When a ball rolls down an inclined plane , it gains speed because of

AI Thread Summary
A ball rolling down an inclined plane gains speed due to the force of gravity acting on it. Conversely, when rolling up an incline, it loses speed as gravity works against its motion. On a horizontal surface, gravity does not contribute to the ball's acceleration because its force acts perpendicular to the direction of displacement, resulting in no work done against gravity. Instead, the only force at play is friction, which affects the ball's motion on a flat surface. Understanding these dynamics is crucial for studying motion and forces in physics.
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When a ball rolls down an inclined plane , it gains speed because of gravity .When rolling up an inclined plane, it loses speed because of gravity .Why doesn't gravity play a role when it rolls on a horizontal surface ?
 
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In an horizontal surface the force of the weight is perpendicular to the displacement so no work against gravity is done if that's what you mean 'gravity doesn't play a role'.
Only work against friction is done.
 
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