Question

Raise a problematic situation in real life, where mechanical physics is needed to solve it. The problem raised should contain the following topics, without being limited to this list. 1. Conservation of mechanical energy. 2. Conservation of the line moment. 3, Rotational dynamics

Answer 1

Consider a situation where a baseball player has hit the ball high into the sky.

As the ball rises, its speed decreases. This can be explained by the principle of conservation of mechanical energy, At the instant, the ball is hit, its speed is high, but as the ball rises, its kinetic energy is converted to gravitational potential energy and thus, the total mechanical energy remains conserved.

If the ball is hit with the lower part of the baseball bat, then it goes with greater velocity as compared to when it is hit with the upper part of the bat, despite the same swing of the bat. This can be explained by rotational dynamics. A similar swing will result in a similar angular velocity but when the ball is struck by a lower part, the R is greater, and since V=w*R, we get a higher velocity of the ball as compared to when R is lower.

As the ball approaches the bat at high speed, its momentum is towards the batsmen, but when it is struck, its direction of momentum changes, this can be understood by conservation of linear momentum. Here, we must consider the bat as well as the ball into the system. When the bat strikes the ball, it imparts impulse onto the ball and in return, its velocity gets decreased by a certain amount, as per the principle of conservation linear momentum.