Question

The velocity of projection of an oblique projectile is vector v = 3i + 2j (in ms^–1). The speed of the projectile at the highest point of the trajectory is 

(a)3ms^–1 

(b) 2ms^–1 

(c) 1ms^–1 

(d) zero

Answer 1

Correct option is (A) 3 ms^-1

The projectile is an example of the motion of a body in 2-Dimension, therefore the velocity vector has components along x-direction component and y-direction component.

At the highest point the velocity component along vertical or y-direction is zero, therefore only horizontal or x-direction component of velocity remains, therefore,

\(\vec v_{\text{ highest point}} = 3\hat i + 0\hat j\)

Hence, the velocity at highest point is,

\(|\vec v| = \) 3 ms^-1

Answer 2

Correct option (a)

Explanation:

At the highest point, velocity is horizontal.