A block is projected at an incline at angle θ. It returns to its initial position with half of its initial speed. Show that the coefficient of kinetic friction is Uk= 3/5 tanθ

Question

anonymous · Answer

Help please need to use work energy theorem.

egenriether · Answer

you mean its "shot" up a ramp?

anonymous · Answer

Im guessing so

egenriether · Answer

ok.  I tried to write on the facing page what I was doing.  I don't know why but my answer is negative.  Can't see how to fix that part, sorry.  Let me know if you have a question, I will be up for just a few more minutes

egenriether · Answer

also note that at E1 the potential energy is 0 (U1=0), so E1=K1. At E2 kinetic energy is 0 (object has stopped) so E2=U2-friction loss.  At E3=K3-2x friction losses; U3=0

anonymous · Answer

looking at it now thanks a ton!

egenriether · Answer

ok!

anonymous · Answer

wow, good job! Looks awesome to me. Not sure why it's negative either, but I'll keep looking at it! Thanks again, cheers!

egenriether · Answer

you got it.

anonymous · Answer

I got it, if I run into any problems or questions, I can ask my sister tomorrow, haha don't want to keep you up. :)