Question

Two particles starting from a point on a circle of radius 4 m in horizontal plane move along the circle with constant speeds of 4 ms^–1 and 6 ms^–1 respectively in opposite directions. The particles will collide with each other after a time of :

• A. 3.0 s
• B. 2.5 s
• C. 2.0 s
• D. 1.5 s

Answer 1

Answer: (B)

2.5 s

Answer 2

\ S₁ + S₂ = 2pr

\ 4t + 6t = 2pr = t = $\frac{2\pi r}{10}$= $\frac{2 \times 3.14 \times 4}{10}$ = 2.5 s