Question

A body is projected with a velocity of 60m/s at 300 to the horizontal. Velocity after 3 seconds

Answer 1

Vertical component = 60sin30 =30m/s
Horizontal component =60cos30= 30squareroot(3)
Time period of ascent =(u sin theta)/g
=3seconds (horizontal component is 30m/s , so 30/10=3)
So at t=3s ,object at highest point. So vertical component of velocity =0
So only horizontal component left(horizontal component does not change as no force acts in that direction)
So speed at t=3s = 30squareroot(3) .i.e the horizontal component of velocity