Question

A person can jump 1.2 m on Earth. How high can he jump on a planet whose density is 1/3rd and radius is 4 times that of Earth, assuming he uses same energy.

Answer 1

We know that,

g ∝ \(\frac {M}{R^2}\)

Now, since same energy is spent

mgph_p = mg_eh_e

⇒ h_p = (g_e/g_p)h_e

\(\frac{3}{4}\) × 1.2m

h_p = 0.9m.