Question

Two hockey players of opposite teams, while trying to hit a hockey ball on the ground collide and immediately become entangled. One has a mass of 60 kg and was moving with a velocity of 5 ms-1 while the other has a mass 55 kg and was moving faster with a velocity of 6 ms-1 towards the first player. In which direction and with what velocity will they move after they become entangled

Answer 1

Answer :-

The final velocity of the two player after getting entangled is 0.26 m/s which is directed towards player 1 or along the direction of player 2.

Explanation :-

Given :

$\sf{}Mass\ of\ the\ first\ player\,m_1= 60kg$

$\sf{}Initial\ velocity\of \ the\ first\ player,u_1= 5m/s$

$\sf{}Mass\ of\ the\ second\ player,m_2= 55kg$

$\sf{}Initial\ velocity\of \ the\ second\ player,u_2= -6m/s$

Note :

We have assume player 1 was moving from left to right,therefore we taken initial velocity as positive and we have assume player 2 was moving from right to left,therefore we have taken it’s initial velocity as negative.

To Find :

Direction and velocity after entangling = ?

Solution :

According of the conservation law of momentum,

$\sf{}m_1u_1+m_2u_2=m_1v_1+m_2v_2$

$\sf{}\implies 60\times 5+55\times -6=60\times v+55\times v$

$\sf{}\implies 300-330=60\times v+55\times v$

$\sf{}\implies -30=(60+55)v$

$\sf{}\implies30=115\times v$

$\sf{}\implies -\dfrac{30}{115}=v$

$\sf{}\therefore v=-0.26$

Hence,the two entangled player wil move with a velocity 0.26m/s from right to left,which is in the direction the second player was moving before collision.