Two particles are projected simultaneously from points O and O′ separated by 10 m horizontally and 5 m vertically as shown. Both are projected with speed 10 m s⁻¹ at 60° to the horizontal in the shown directions. Time after which their separation is minimum is:
Options

Question

Two particles are projected simultaneously from points O and O′ separated by 10 m horizontally and 5 m vertically as shown. Both are projected with speed 10 m s⁻¹ at 60° to the horizontal in the shown directions. Time after which their separation is minimum is:

Options

G1 Physics · Accepted Answer

Both projectiles have the same gravitational acceleration, so their relative acceleration is zero. Relative motion is uniform. Using the initial separation vector from the figure and the difference of the two launch velocities, tₘᵢₙ=-(r₀·vᵣ)/|vᵣ|²=1 s. Option B.