Question

In the figure shown below, find the system which can be considered as a rigid body.

• A. $(A+B)$ system
• B. $(A+C)$ system
• C. $(B+C)$ system
• D. $(A+B+C)$ system

Answer 1

The correct option is A $(A+B)$ system

$A+B$ system has no velocity of seperation or approach
$\therefore$ $A+B$ system can be considered as a rigid body.
$A+C$ system, $B+C$ system and $A+B+C$ system has velocity of seperation (or) velocity of approach.
$\therefore$ they cannot be considered as rigid bodies.