Question

The velocity of a projectile at the initial point A is $(2\hat{i}+3\hat{j})$. Its velocity at point B is

• A. $-2\hat{i}-3\hat{j}$
• B. $-2\hat{i}+3j$
• C. $2\hat{i}-3\hat{j}$
• D. $2\hat{i}+3j$

Answer 1

Answer: (C)

$2\hat{i}-3\hat{j}$

A projectile has constant horizontal below,

If it has no acceleration in horizontal direction.

Here,

At point B,

Considering only vertical motion,

it will be free fall case, and A and B on same level,

Will have same and opposite speeds.

So,

Vertical velocity at B=$-3\hat{j}$,

Horizontal velocity at B=$2\hat{i}$,

Hence , $v_B=(2i-3j)$

Option $\text{C}$ is the correct answer