OnlineCBT
Physics · PYQ NEET UG 2021
हिन्दीA car starts from rest and accelerates at \( 5\text{ m/s}^2 \). At \( t = 4\text{ s} \), a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at \( t = 6\text{ s} \)? (Take \( g = 10\text{ m/s}^2 \))
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Correct answer · Option C
\( 20\sqrt{2}\text{ m/s}, 10\text{ m/s}^2 \)
Explanation
At \( t=4\text{ s} \), horizontal velocity \( v_x = at = 5 \times 4 = 20\text{ m/s} \). Vertical velocity at \( t=6\text{ s} \) (2 s after drop) is \( v_y = g\Delta t = 10 \times 2 = 20\text{ m/s} \). Total velocity = \( \sqrt{20^2 + 20^2} = 20\sqrt{2}\text{ m/s} \). Acceleration after release is only due to gravity, so \( a = g = 10\text{ m/s}^2 \).
