Two masses are placed on top of a building. The mass of one is twice the mass of the other. Both are dropped at the same time. Neglecting air resistance, which statements are true?
1. Both objects have the same potential energy at the top
2. Both objects fall with the same acceleration
3. Both objects have the same kinetic energy before hitting the ground
4. Both objects have the same speed when they hit the ground
A. 1, 2
B. 1, 3
C. 2, 4
The Attempt at a Solution
I know 1 and 2 are definitely true.
But I also thought 3 and 4 were true since for 4, I could use the kinematic equation
v2 = v02 + 2ay
And since a and y and v0 are the same for both, I thought they'd have the same final velocity and thus, the same kinetic energy.
But is that not true?