Question

3.when a hockey player hits a hockey puck with his stick, the velocity of the puck changes from 8.0 m/s n to 10.0 m/s s over a time interval of 0.050 s. what is the acceleration of the puck?

Explanation:

Step1: Define velocity vectors

Let the north direction be positive. So initial velocity \( v_i = 8.0\ m/s \), final velocity \( v_f=- 10.0\ m/s \) (since south is opposite to north), and time \( \Delta t = 0.050\ s \).

Step2: Use acceleration formula

The formula for acceleration is \( a=\frac{v_f - v_i}{\Delta t} \).
Substitute the values: \( a=\frac{- 10.0 - 8.0}{0.050} \)
First, calculate the numerator: \( - 10.0 - 8.0=-18.0\ m/s \)
Then divide by time: \( a=\frac{-18.0}{0.050}=- 360\ m/s^2 \)
The negative sign indicates the acceleration is in the south direction.

Answer:

The acceleration of the puck is \( 360\ m/s^2 \) [S] (or \( - 360\ m/s^2 \) if north is taken as positive).