Question

A body is moving with velocity 30 m/s towards east. After 10 seconds its velocity becomes 40 m/s towards north. The average acceleration of the body is

Answer 1

Initial velocity $u=30\hat{i}$

Final velocity $v=40\hat{j}$

Change in velocity $\Delta v=40\hat{j}-30\hat{i}$

Magnitude $|\Delta v|=\sqrt{{30}^2+{40}^2}=50$

Average acceleration $a=\frac{|\Delta v|}{\Delta t}=\frac{50}{10}=5m/s^2$