(II) A sled is initially given a shove up a frictionless 23.0° incline. It reaches a maximum vertical height 1.22 m higher than where it started at the bottom. What was its initial speed?

4.88 m/s

Explanation:

Using the law of conservation of energy, we know that energy can neither be created nor destroyed but can only be transformed from one state to another. Therefore, the kinetic energy at the inclined bottom equals to the potential energy at the top hence

and making v the subject of the formula then where m represnt the mass of sled, v is the initial speed, g is acceleration due to gravity and h ia the vertical height. Substituting g with 9.81 m/s2 and h with 1.22 then

heats surface water up

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