An object is released from rest at height h = 5.0\text{m} (ignore air resistance, g \approx 10\text{m/s}^2). How fast is it moving just before hitting the ground?

10\text{m/s} mgh = \tfrac{1}{2}m v^2 \Rightarrow v = \sqrt{2gh} = \sqrt{2(10)(5)} = 10\text{m/s}.

Conservation of Energy

AP Physics 1· difficulty 2/5

h = 5.0~\text{m}

Explanation

mgh = \tfrac{1}{2}m v^2 \Rightarrow v = \sqrt{2gh} = \sqrt{2(10)(5)} = 10~\text{m/s}

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