Answer: the required height is 2.5 m
Step-by-step explanation:
given the given data in question
Lime to come in rest;
using S = ((U1 + U2)/2) t
⇒ 0.5 = ((√(2gh) + 0)/2) t
t = (0.5 × 2) / √(2gh)
now fat = impulse = change in momentum dp
F = 5mg = dp/dt = [(m√(2gh))/(0.5 × 2)] × √(2gh)
5mg = 2mgh/(0.5 × 2)
5 = h / 0.5
h = 5 × 0.5
h = 2.5 m
Therefore the required height is 2.5 m