Understanding Uniform Circular Motion to Solving Problems

[Sarina3003]

1. Homework Statement

Homework Equations

equations is not needed here

The Attempt at a Solution

I have no idea :(
Please help me![/B]

 

[TomHart]

They are asking which shadow is moving the fastest on the ground. What direction of motion produces a moving shadow? Is there a direction of motion that does NOT produce a moving shadow? Maybe you could experiment by watching the shadow your hand makes if you place it directly beneath a source of light.

Edit: P.S. Welcome to Physics Forums.

 

[Sarina3003]

Thanks for that. However, i don't quite follow you ;(

 

[PeroK]

Thanks for that. However, i don't quite follow you ;(

You need to be able to attempt the question yourself. We can help you when you get stuck.

Tom has suggested you carry out a simple experiment. It's difficult to see why you can't do that. Do you have a lamp and a table? Can you move your hand in a circle?

Even if not, you should be able to imagine what happens using the diagram you posted.

 

[haruspex]

Thanks for that. However, i don't quite follow you ;(

Tom's suggested experiment is very easy. With a light overhead, rotate your arm in front of you so that your hand moves in a vertical circle at a constant rate. Watch the shadow. When the shadow is moving most slowly, what is yiur hand doing? What about when the shadow moves fastest?

Edit,.. PeroK pipped me.

 

[Sarina3003]

Thank you. However it's really hard
to see by naked eyes and my hands could not move at a constant rate eithe. But i think it could be B because i have thought of simple harmonic motion :|. B is equilibrium postion and V is max there , not really relevant but that's the only thing that my brain could say to me :(

 

[haruspex]

Thank you. However it's really hard
to see by naked eyes and my hands could not move at a constant rate eithe. But i think it could be B because i have thought of simple harmonic motion :|. B is equilibrium postion and V is max there , not really relevant but that's the only thing that my brain could say to me :(

Good reasoning. The horizontal component of motion is indeed SHM.

 

[Sarina3003]

Thank you so much!