Bowling Ball problem

[parwana]

A bowling ball is suspended from the ceiling of a lecture hall by a strong cord. The ball is drawn away from its equilibrium position and released from rest at the tip of the demonstrator's nose, as shown in Figure Q5.8.

If the demonstrator remains stationary, explain why the ball does not strike her on its return swing.

Would this demonstration be safe if the ball were given a push from its starting position at her nose?

yes
no
I know its no, but I can't put it into words why. Please help

Explain.

 

[Max Eilerson]

Conservation of energy.

 

[parwana]

^ can you provide a more detailed explanation on both please

 

[AVD]

neglecting air resistance, Kinetic energy would be conserved & the ball would not go any further than its starting point (this is common sense)

However, if there is a push at the beginning, there is an initial kinetic energy, meaning on its return swing, the ball will go further than the point from where it was pushed until Ke = 0. Since Ke did not equal 0 on the initial swing (if there is a push), it would not equal zero at that same point upon its return, meaning it would still be in motion, meaning it would clock her in the face :)

I know my explanation isn't exactly clear but I hope it helps

 

[parwana]

thank u that helped