Question

A particle $P$ is projected with speed $20m/s$ at angle ${37}^o$ from horizontal as shown in figure. At the same instant $Q$ starts from same point and moves with uniform acceleration towards right. Path of the particle $P$ w.r.t $Q$ is straight line. Acceleration of $Q$ is:

• A. $40{m/s}^2$
• B. $20{m/s}^2$
• C. $\frac{20}{3}{m/s}^2$
• D. $\frac{40}{3}{m/s}^2$

Answer 1

The correct option is D $\frac{40}{3}{m/s}^2$

P to be in straight line with respect to Q the acceleration components perpendicular to the line of particle P should be zero.

$a\sin {37}^{\circ }=g\cos {37}^{\circ }$

$a=g\cot {37}^{\circ }=\frac{40}{3}m/s^2$