Answer:
80 m or 81.3 m
Explanation:
Initially it had no velocity(as at rest). Let the height be h
Using conservation of energy:
Initial KE + PE = final KE + PE
(1/2) m(0)² + mgh = (1/2) m(40)² + mg(0)
mgh = (1/2) m (1600)
2gh = 16000
h = 1600/(2*10) {for g = 10}
h = 80
80 For g = 9.8, h = 81.3 m
Using Newton's eqⁿ of motion:
v² = u² + 2aS
40² = 0² + 2(g)S
1600/2g = S
For g = 10, S = 80 m
g = 9.8, S = 81.33 m
