Question

a body is projected with an initial velocity 20 m per second at 60 degrees to the horizontal. It's initial velocity vector is,

Answer 1

Its initial velocity in the x-direction is 20cos60°
=20/2=10m/s.

initial velocity in y direction=20sin60°=20√3/2=10√3m/s.

so velocity vector is 10i^ +10√3j^.

Answer 2

Given that,

Initial velocity of a body is 20 m/s

It is projected at angle of 60 degrees

To find,

Its initial velocity vector.

Solution,

Initial velocity vector is the sum of horizontal and vertical velocity. So,

$\vec{v}=v\cos\theta i+v\sin\theta j\\\\\vec{v}=10\times \cos(60) i+20\times \sin(60) j\\\\\vec{v}=5i+17.3j$

Hence, the initial velocity vector is $\vec{v}=5i+17.3j$.