Question

Help work ?

Answer 1

`F_r approx 2250` [N]

Explanation:

Calling

`m_1 = 4.5` released mass
`m_2 = 0.050` nail mass
`h_1 = 1` height at which the mass `m_1` is released
`h_2 = 0.020` embedded distance
`g = 9.8` gravity acceleration
`F_r =` constant friction force

We have before the hit

`m_1 g h_1 = 1/2 m_1 v_1^2 = E_1`

Energy absorbed after the collision until rest

`E_1 + (m_1+m_2)h_2 g = F_r h_2` then

`F_r = (m_1 g h_1 + (m_1+m_2)h_2 g)/h_2`

and substituting values

`F_r approx 2250` [N]