The sledder shown inFigure 1starts from the top of a frictionless hill and slides down into the valley. Suppose that h1 = 4.5 m &h2 = 5.8 m?

What initial speed vi does the sledder need to just make it over the next hill?

Express your answer to two significant figures and include the appropriate units.


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1 Answer

  • 1 month ago

    Conservation of Energy... 

    E hill 1  =  E hill 2

    E hill 1 =  PE  + KE  =   mg(h1)  + (1/2)m(v1)^2

    E hill  2  =    mg(h2)  + (1/2)m(v2)^2   

       v1 = velocity on hill  1           v2 = velocity on hill 2 

     h1  = height  first hill on left         h2 = height hill on the right

             mg(h1)  + (1/2) m (v1)^2     =    mg(h2)  + (1/2) m (v2)^2  

    we  know  h1 , h2,   g   

    AND      v2 = 0  if you JUST make it to the top of the hill #2

     Notice  m  cancels out on both sides   !

    Now  solve  for   v1 ... I got an answer between  5  to 6 m/s   .............   You do the work.

    Don't forget to choose a Best Answer.....

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