Ncert Exercises & Solutions

A hockey player is moving northward and suddenly turns westward at the same speed to avoid an opponent. The force that acts on the player is

1. frictional force along westward
2. muscle force along southward
3. frictional force along south-West
4. muscle force a south-West

Step 1: Find the direction of change in momentum.

Consider the adjacent diagram

Let,

\begin{array}{l} OA = p_{1} \\ = Initial momentum of player northward \\ AB = p_{2} = Final momentum of player towards west. \\ Clearly, OB = OA + AB \end{array}

in momentum

= p_{2} - p_{1}

= AB - OA = AB + (-OA)

= Clearty ræultant AR will along souttm-west.