A body of mass 1 kg is moving with velocity 30 ms^(-1) due north. It is acted on by a force of 10 N due east for 4 seconds. Find the velocity of the body after the force ceases to act.

A body of mass 1 kg is moving with velocity 30 ms^(-1) due north. It i

1.	A body of mass 1 kg is moving with velocity 30 ms^(-1) due north. It is acted on by a force of 10 N due east for 4 seconds. Find the velocity of the body after the force ceases to act.
Answer» Solution :M = 1 kg, F = 10 N due east , t = 4s , u = 0. `a=(F)/(M)=(10)/(1)=10 ms^(-2)` due east. Final velocity due east at the END of 4 SECONDS, v = u + at `= 0+10(4)=40 ms^(-1)`. The body has initial velocity `30 ms^(-1)` due north. Which is not effected by applied force. At the end of 4 seconds, its velocity is `(40hat(i)+30hat(j))`. `V=sqrt((40)^(2)+(30)^(2))=50 ms^(-1)` Direction of resulant velocity : `tan alpha = (30)/(40)=(3)/(4)` The resultant velocity makes an angle `alpha = tan^(-1)((3)/(4))` North of east.