Question

A particle moves towards East for $2s$ with velocity $15m/s$ and move towards North for $8s$ with velocity $5m/s$. Then, average velocity of the particle is

• A. $1m/s$
• B. $5m/s$
• C. $7m/s$
• D. $10m/s$

Answer 1

Answer: (B)

$5m/s$

Displacement along East $AB=speed\times time=15\times 2=30m$

Displacement along North $BC=5\times 8=40m$

Thus, total displacement $AC=\sqrt{{30}^2+{40}^2}=50m$

Total time taken $=2s+8s=10s$

Average velocity $=\frac{\text{total displacement}}{\text{total time}}=\frac{50m}{10s}=5m/s$

The direction of average velocity will be along the displacement, i.e in North-East direction.