Solar energy, wind energy, and hydroelectric energy are all renewable energy
Hey there,
Your question states: What factors affect the speed of water waves
Let's get one thing out the way, (wavelength) does

affect the the speed of water. If anything, it would be how high the wavelength's are. The higher the wavelengths are, the more that it would affect the speed, because there very high, but if it were to go longer on the width side, that would increase the speed, but that's not the case. Your correct answer would be (higher wavelength).
Hope this really helps you.
Answer:
So the conclusion is that in presence of air net force acting downward reduces for feather and hence falls slower than coin. But in absence of air resistance, net downward force is just equal to force due to gravity which is same for both coin and feather and hence they fall down at the same rate.
I,think potential energy is mgh so 65*100*9,81