Q17 of 46 Page 247

Two balls of masses in ratio 2:1 are dropped from the same height. Neglecting air resistance, find the ratio of

(i) the time taken for them to reach the ground.


(ii) the forces acting on them during motion.


(iii) their velocities when they strike the ground.


(iv) their acceleration when they strike the ground.

(i) 1:1. This is because the equations of motion are independent of the masses of the 2 balls. So they take equal amounts of time to reach the ground.

(ii) 2:1. We know F = ma. ’a’ in this case is the acceleration due to gravity, g. So force depends only on m, and here the masses are in 2:1 ratio.


(iii) 1:1. This is because the equations of motion are independent of the masses of the 2 balls.


(iv) 1:1. The acceleration due to gravity, g is independent of the masses of the 2 balls.


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