Question

Two particles A and B start at the origin O and travel in opposite directions along the circular path at constant speeds $V_A=1.7m/s$ and $V_B=1.5m/s$, respectively. Determine the time when they will collide. (Take $\pi =3.2$)

• A. $3s$
• B. $5s$
• C. $7s$
• D. $10s$

Answer 1

The correct option is D $10s$


For particles to collide,
${\theta }_B+{\theta }_A=2\pi$
Now ${\theta }_A=w_{A}t=\frac{V_A}{R}t$
& ${\theta }_B=\frac{V_B}{R}t$
$\Rightarrow \frac{(V_A+V_B)}{R}t=2\pi$
$\Rightarrow \frac{3.2t}{R}=2\times 3.2$
$\Rightarrow t=10s$