Question

A particle is moving eastward with a velocity of 5 m/s.In 10s, the velocity of the particle changes to 5m/s northward.The average acceleration in this time is:

a) 1/√2 m/s²

b) 1/√2 m/s²

c) 1/2 m/s²

d) Zero

Answer 1

Initial velocity eastward = 5m/s
Final velocity in E-W direction = 0
so change in velocity = -5m.s in eastward direction = 5m/s westward
so average acceleration in E-W direction is 5/10 = 0.5 m/s^2 in westward direction

Initial velocity in N-S direction = 0
Final velocity in N-S direction = 5m/s northward
so change in velocity in N-S direction = 5m/s northward
so average acceleration in N-S direction = 5/10 = 0.5m/s^2 northward

Resultant acceleration is found by adding the 2 acceleration vectors
0.5 m/s^2 due west and 0.5 m/s^2 due north . We add them using the parallelogram law as seen in the figure below

The reultant is the diagonal of the recatngle =