Question

Calculate the final velocity right after a 119 kg rugby player who is initially running at 7.65 m/s collides head‑on with a padded goalpost and experiences a backward force of 17500 N for 5.50×10^−2 s.

Answer 1

SOLUTION:

m= mass of player = 119 kg

F=-17500 N [ negative sign means force is backward]

= initial velocity

lets  

final velocity

I= Impulse

we know v that,

......................(1)

From impulse momentum theory

their negative sign is backward direction define

the final velocity is =0.44 m/s