A 10.7 g CD with a radius of 6.06 cm rotates with an angular speed of 30.9 rad/s. What is its kinetic energy?
What angular speed must the CD have if its kinetic energy is to be doubled?
Here is my work:
kinetic energy energy = 1/2 m v2
= 1/2 m ( r ω )2...
how do i figure out the velocity and the acceleration?
I need the velocity for the centripetal force equation & I need the acceleration for the f=ma equation.
thanks so much.
I get 0.0641 m when i figure it out my way and that answer is incorrect. Maybe I am doing some math wrong, but I double checked? What answer do you get if you use my above equation?
Are you sure it is the right equation to use?
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I have gotten hints from the teacher also. we have emailed back and forth. Before I did get help from him I tried a lot of numbers I came up with on LON CAPA, therefore, I only have one more try left, so I want to make sure I am doing it the right way. I know I am close and I have the right...
So I figured out the first answer. It is 0.391 m. Now I need to figure out the time. When i put it in the equation i get two answers...0.286 and 0.278...my equation is
0.391 = 2.77t - .5(9.81)t^2
What is the correct answer for the second part of the problem originally posted in the...
Hey, thank you so much for that advice Hoot. I was putting in -4.06 and i tried it without the negative and it worked. THANK YOU. Can you look at my other problem I posted ??? please!
anyone else have any advice on this one? the above advice didnt really help me. I need some step by step instructions or something. i have been working on this problem for too long.
even if i switch the two v's i end up with the same answer just different sign, unless i am not supposed to put in 0.510 for x. I am ready to quit physics.
so v^2 is 40.61, what should I put in for v_o? and what should I put in for the change in x in that equation. If i put in 0 as initial velocity and change in x as 0.510 i end up with acceleration -39.81, divide that by 9.81 and i get -4.06 which was incorrect according to lon capa.
I don't know any of those formulas or anything you listed above. I just started physics so we haven't gotten to those yet. Thanks for letting me know I got the first part right. I need things in simple terms I guess.