Do not worry if you don't recognize both parts of the problem at this point. If you recognize the dynamics problem,<span> On the other hand, if you recognize this as a kinematics problem you will quickly see that you need to find angular acceleration before you can begin and so will need to do that pre-step first.</span>
The frequency at which the body vibrates breaks is natural frequency. The glass with her voice because the frequency of her voice matches the natural frequency of the glass.
<h3>What is the natural frequency?</h3>
When there is no external force acting on the body unless the body vibrates is known as the natural frequency of vibration.it is denoted by 
.
when the frequency of a body matches the natural frequency a condition occurs known as resonance.
To learn more about the natural frequency refer to the link;
brainly.com/question/1123932
13/2 = 6.5 Km/h
That’s 6500/3600= 1.8 m/s
I'm happy to know that the diagram shows how it's all set up.
If I could see the diagram, then I could probably do a much
better job with an answer. As it is ... 'flying blind' as it were ...
I'm going to wing it and hope it's somewhat helpful.
If the pulley is movable, then I'm picturing one end of the rope
tied to a hook in the ceiling, then the rope passing down through
the pulley, then back up, and you lifting the free end of the rope.
A very useful rule about movable and combination pulleys is:
the force needed to lift the load is
(the weight of the load)
divided by
(the number of strands of rope supporting the load) .
With the setup as I described it, there are 2 strands of rope
supporting the load ... one on each side of the pulley. So the
force needed to lift the load is
(250 N) / 2 = 125 N .
