Answer:
4.4 m/s
Explanation:
Initially, the rock has only potential energy. As it falls, some of the potential energy is converted to kinetic energy.
PE₀ = PE + KE
At one point, the potential energy and kinetic energy are equal.
PE₀ = KE + KE
PE₀ = 2 KE
mgh₀ = 2 (½ mv²)
gh₀ = v²
(9.8 m/s²) (2.0 m) = v²
v = 4.4 m/s
