Science questions in details [4 marks ]

The feeling of lightness or floating experienced on a swing just after it reaches its highest point and begins to descend is due to a change in acceleration and the resulting sensation of reduced gravitational force. As the swing moves upward, it slows down, and at its highest point, it momentarily stops before changing direction. During this brief moment, the force of gravity is still acting on us, but it’s not counteracted by any upward force from the swing, leading to a feeling of weightlessness. As the swing starts to descend, we accelerate downwards, and the feeling of lightness intensifies because our body is essentially falling with the swing.

The ball’s motion is governed by the forces of gravity and friction. On the inclined plane, gravity provides the acceleration for the motion. On the horizontal surface, only friction acts on the ball.
• Stopping before A: Increasing friction on the horizontal surface will cause the ball to decelerate more rapidly, meaning it will come to a stop sooner, potentially before reaching point A.
• Stopping after A: Decreasing friction on the horizontal surface will reduce the deceleration, allowing the ball to travel further before losing all its kinetic energy and stopping.

When a ball is thrown upwards, the only force acting on it throughout its entire motion is gravity, which pulls it downwards. However, depending on the motion of the ball, the direction of this force relative to the ball’s velocity changes.
1. During its upward motion: The force of gravity is downwards, opposing the upward motion of the ball, causing it to slow down.
2. During its downward motion: The force of gravity is still downwards, but now it aligns with the ball’s direction of motion, accelerating it downwards.
3. At its topmost position: The ball has zero velocity, meaning it’s momentarily stationary. At this point, the force of gravity is still downwards, but since the ball is not moving upwards or downwards, it has no net effect on the ball’s motion.