A particle undergoes SHM. The graph below shows how the kinetic energy EK of the particle varies with the displacement x of the particle from equilibrium.

Question

deoxna · Answer

I'll upload the word document, but I need help with question 6.

anonymous · Answer

can you save that as a screen shot or something?

deoxna · Answer

This the relevant graph, but my question is the following, how to find the maximum velocity using the maximum kinetic energy?

anonymous · Answer

Two points probably...  ie  
$$KE _{1} / KE _{2}$$

anonymous · Answer

mass cancels... hmm still doesn't give enough info. though... do you know anything about the spring (k for example)?

deoxna · Answer

I calculated the spring using the formula ME=PE+KE=(1/2)(K)(A)², where the amplitude is 0.05 m
PE+KE=0.06=1/2k(0.05)² -> k=48

anonymous · Answer

good point...   let me think about it for a minute or two

anonymous · Answer

still there?

deoxna · Answer

yes, I'm going over my notes to find other formulas...

anonymous · Answer

Think I came up with something...

anonymous · Answer

$$V _{\max} = (k/m)*x _{\max}$$

anonymous · Answer

you can use that in
$$1/2*m*(V _{\max})^{2} = .06J$$

anonymous · Answer

v= sq root (k/m) x

anonymous · Answer

Yes    wrong bracket use in the equation editor   sorry..

deoxna · Answer

I found the equation: $$v=\sqrt{\frac{ k }{ m }}\sqrt{A^2-x²}$$, which simplifies to V=wA

anonymous · Answer

yes...it's right but how u'll get omega?

anonymous · Answer

in fact which is ur next question...find d angular frequency

anonymous · Answer

there is another relation also k=m (w)^2...but it also won't help.

deoxna · Answer

Also, -kx=ma

anonymous · Answer

but i dont think there is any use of acceleration term  in this question.

anonymous · Answer

from where u got this question...some assignment?

deoxna · Answer

Yeah, but what I'm thinking is that this might be unsolvable without mass, and my teacher may have forgotten to include it

anonymous · Answer

Yes..it seems like that.

deoxna · Answer

Or, we have been looking at spring-mass systems, whereas pendulums are also shm that dont depend on mass.

anonymous · Answer

but u need length of the pendulum

deoxna · Answer

yeah... I just realized that...

deoxna · Answer

Anyway, I'll just let it be and tell him I couldn't solve it. But anyway thanks alot for helping me.

anonymous · Answer

:)