Question

A bus moves over a straight level road with a constant acceleration $a$. A body in the bus drops a ball outside. The acceleration of the ball with respect to the bus and the earth are respectively

• A. $a$ and $g$
• B. $a+g$ and $g-a$
• C. $\sqrt{a^{2}+g^{2}}$ and $g$
• D. $\sqrt{a^{2}+g^{2}}$ and $a$

Answer 1

Answer: (C)

Let $a _{ rel }=$ acceleration of ball with respect to groundacceleration of bus with respect to ground.

$=-g \hat{ i }-a \hat{ j }$
$\mid a _{\text {rel }}\mid=\sqrt{g^{2}+a^{2}}$