a) A watermelon with a mass of 2.0kg falls out of a tree house that is 5.4m above the ground. What is the speed of the watermelon just before it hits the ground?
First I found Eg to be 105.9 J based on the formula Eg = mg (h2 - h1).
Since the watermelon hits the ground, Eg = Ek. Then I found the velocity to be 10.29m/s from the formula v = sq.rt (2 Ek / m).
I (hopefully) did this part properly.
b) A cantaloupe with a mass of 0.45kg falls out of the other side of the tree house. It hits a tree branch at a speed of 6.3 m/s. How high is the tree branch from the ground?
This is the part I'm having a bit of trouble with.
The only thing I can think of using is the formula for height.
h = ((v1)^2 - (vf)^2) / 2g
h = (0 - (6.3m/s)^2) / (2 * 9.81m/s^2)
h = -2.02m
Then 5.4m - 2.02m = 3.38m from the ground to the branch.
When I do it this way, I'm not using the information given in the question, which was the mass, 0.45kg. So, I think I'm doing it incorrectly. Can anybody help me out? Thanks!