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Conservation of Energy

  • Thread starter KTiaam
  • Start date
  • #1
53
1

Homework Statement



A mass m = 2 is in free fall. The acceleration of gravity is g = 10. All numbers are in mks units. The position y(t) and velocity v(t) of the mass as a function of time t are y(t)=9−5t2 and v(t)=−10t. Find each of the energies (K,U,E) as a function of time t. Hint: substitute v(t) into K(v), substitute y(t) into U(y).

Homework Equations



k = 1/2mv2
u = mgy


The Attempt at a Solution



I know that:
Work = ΔK
-ΔU = ΔK

im having trouble switching the equation to a function of time.
Am i trying to approach the problem in the wrong way?

any help is appreciated. Thanks!
 
Last edited:

Answers and Replies

  • #2
82
3
Your formula for ##U## is a little off. (Hint: check your units!)
 
  • #3
53
1
oh okay i solved the problem thank you!
 
  • #4
82
3
Sure thing, happy to help!
 

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