Question

a hammer of mass 1 kg falls freely from a height of 2m . calculate (1) the velocity and (2) the K.E of the hammer just before it touches the ground .

Answer 1

$the \: velocity \: will \: be \: \sqrt{2gh} = \\ \sqrt{2 \times 10 \times 2} = \sqrt{40} m {s}^{ - 1} \\ now \: kinetic \: energy = \frac{1}{2} m {v}^{2} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 0.5 \times 1 \times 40 = 20j$