Given; potential energy on the Earth’s surface Ui = – 54 J; mass of the body m = 3 kg
If the body escapes, then its potential energy at infinity Uf = 0
Escape energy = Uf – Ui = 0 – (-54) = 54J
or \(\frac{1}{2} m v_{e}^{2}\) = 54
or ve = \(\sqrt{\frac{2 \times 54}{m}}=\sqrt{\frac{2 \times 54}{3}}=\sqrt{36}\)
or ve = 6 ms-1