Question

a particle is moving with a velocity of 5m/s .after 5sec it is found to be moving with velocity of 12 m/s in a direction perpendicular to the original direction.during these 5sec find
1.change in speed,
2.change in velocity and magnitude of change in velocity ,
3.average acceleration and its magnitude .

Answer 1

1) change in speed: 12-5 = 7m/s
2) V1=5i & V2=12j
Change in vel.= V2-V1 = 12j-5i
its magnitude = sqrt(12^2+5^2)
= 13m/s^2
3) x-dir.: 0=5+Ax*5 => Ax= -1m/s^2
y-dir.: 12=0+Ay*5 => Ay= +12/5=2.4m/s^2
So A = -1i+2.4j
Mag. of av. acc.=sqrt(Ax^2+Ay^2)