# 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.

PLZ HELP ASAP

### 1 Answer

- MathguyLv 51 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.

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