Alright I have a few problems here.(adsbygoogle = window.adsbygoogle || []).push({});

1). A bird is flying with a speed of 18 m/s over water when it accidentally drops a 2 kg fish. If the altitude of the bird is 5.40 meters and friction is disregarded, what is the speed of the fish when it hits the water?

My work: I don't know if I did this one right so if you could check that would be great.

I did PE= (2kg)(9.81m/s^2)(5.4m) = 106 PE

So I made KE at the point of the water 106 KE and 0 PE (potential energy.)

Then I did 106 = 1/2 * 2kg * v^2

I got it to equal v = 10.29 m/s is that correct?

2) A 755N Diver drops from a 10 m boarding above the waters surface. Find the divers speed 5 meters above the water. Then find the diver's speed just before it hits the water.

ok here i got 9.9 m/s for the part 5 meters above water is that correct? and then I got 14 m/s when striking the water?

(Part B) If the same diver leaves the board with initial upward speed of 2.0 m/s find the divers speed when striking the water.

I worked it out until here now I dont know what to do next

3) An Olympic runner leaps over a hurdle. If the runners initial vertical speed is 2.2 m/s how much will the runners center mass be raised during the jump?

Work: im not really sure what to do here but is the answer .5 meters up?

I don't know if this is a correct equation, but I did V^2 = mgh

4) A pendulum bob is released from some initial height such that the speed of the bob at the bottom of the swing is 1.9 m/s. what is the initial height of the bob?

Ok here i don't know what to do really. I think it goes along the lines of one above, but im not sure if that was right either.

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# Homework Help: Help with conservation of Mechanical Energy

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