How much of the total energy in Problem 3 and 4 has been transformed to kinetic energy?

I am only a HS Freshman so I might be wrong

3. Its potential energy and the formula for PE = mgh so you would use the weight given (Weight = mg) and mg is in the (Potential Energy) forumula so we multiply 3 by 30 and get 90 Joules

4. We would do the same thing with this: PE = mgh; PE = 10*3 = 30 Joules

Once again I am only a Freshman and I have taken Private AP Physics classes so just maybe wait for someone who is more confident.

This is just what I would answer

btw, for problem 5, the fromula for kinetic energy is 1/2*m*v^2

I think the correct answer would be one half the wavelength. Waves would "feel bottom" when the water is at the depth of 0.5 of the wavelength. "Feel bottom" is a term used to describe that the depth of water affects the wave properties. Hope this answers the question.