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
Initial velocity u=30^i
Final velocity v=40^j
Change in velocity Δv=40^j−30^i
Magnitude |Δv|=√302+402=50
Average acceleration a=|Δv|Δt=5010=5 m/s2