Question

Three balls of different masses are thrown at different instants up against gravity. While all the three balls are in air, the centre of mass of the system of three balls has an acceleration:

• A. equal to ${}^{\prime }{g}^{\prime }$
• B. which depends on the velocities, heights and masses of the balls
• C. which depends on the direction of motion and speeds of different balls
• D. which depends on the direction of motion, speeds and masses of the ball

Answer 1

The correct option is A equal to ${}^{\prime }{g}^{\prime }$

If $m_1,m_2,m_3$ be the masses of the balls, the acceleration corresponding to each ball is $g$. Acceleration of centre of mass will be,

$\overline{a}=\frac{m_{1}g+m_{2}g+m_{3}g}{m_1+m_2+m_3}=g$