Question

Two particles are projected under gravity with speed $4$ m/s and $3$ m/s simultaneously from same point and at angles ${53}^{\circ }$ and ${37}^{\circ }$ with the horizontal surface respectively as shown in figure. Then :

• A. Their relative velocity is along vertical direction.
• B. Their relative acceleration is non-zero and it is along vertical direction.
• C. They will hit the surface simultaneously
• D. Their relative velocity is constant and has magnitude 1.4 m/s.

Answer 1

Answer: (A), (D)

The correct options are
A Their relative velocity is along vertical direction.
D Their relative velocity is constant and has magnitude 1.4 m/s.

$v_1=4cos{53}^0\hat{i}+4sin{53}^0\hat{j}$
$v_2=3cos{37}^0\hat{i}+3sin{37}^0\hat{j}$
$v_{12}=\frac{7}{5}\hat{j}=1.4\hat{j}$
Relative velocity in horizontal direction is zero.