Question

A 72.0 kg swimmer jumps into the old swimming hole from a tree limb that is 4.00 m above the water.
Part A- Use energy conservation to find his speed just as he hits the water if he just holds his nose and drops in.
Part B- Use energy conservation to find his speed just as he hits the water if he bravely jumps straight up (but just beyond the board!) at 2.35 m/s .
Part C- Use energy conservation to find his speed just as he hits the water if he manages to jump downward at 2.35 m/s .

Answer 1

(1/2) m v^2 = m g h

(1/2) m v^2 = m g h + (1/2)m(2.3^2)

exactly the same. These trick questions should not be getting to you. If you need to think about it if he jumps up at 2.35 he will pass the end of the board at 2.35 on the way down.

Answer 2

8.88