Question

Two rugby players run towards each other and have an inelastic collision. Given the mass 70 kg and 60 kg respectively, and velocity 3 ms^-1 and 4 ms^-1. Calculate the final velocity and its direction of the respective players. Discuss how a rugby player’s bone develops if continuously performing the weight bearing exercise using Wolff’s Law and bone remodeling theory.

Answer 1

Given:

$m_1=70\:\rm kg$

$m_2=60\:\rm kg$

$v_1=3\:\rm m/s$

$v_2=4\:\rm m/s$

The law of conservation of momentum says

$$m_1v_1+m_2v_2=(m_1+m_2)u$$

The speed of players

$$u=\frac{m_1v_1+m_2v_2}{m_1+m_2}=\frac{70*3+60*4}{70+60}=3.5\:\rm m/s$$

The velocity is directed toward direction of motion 60 kg player.