Question

Two balls of same mass are projected from tall building . One is vertically upward and other vertically downwards with same speed under gravity . If Acceleration due to gravity is g then Acceleration of their center of mass is

Answer 1

The acceleration of the ball projected vertically upwards will be -g while that of the ball projected vertically downwards will be g.

Then the acceleration of the center of mass will be,

$\displaystyle\longrightarrow\sf{\bar a=\dfrac {m(-g)+mg}{m+m}}$

$\displaystyle\longrightarrow\sf {\underline {\underline {\bar a=0}}}$

where m is the mass of each ball, which is given as same.