Question

he system is at rest to begin with. Which of the following bodies (masses) would have acceleration(s) immediately after the lower thread has been cut. Assume ideal conditions for springs, strings and the pulley.

• A. ${\text{m}}_1$ and ${\text{m}}_2$
• B. Only ${\text{m}}_4$
• C. ${\text{m}}_2$ and ${\text{m}}_4$
• D. ${\text{m}}_3$ and ${\text{m}}_4$

Answer 1

The correct option is B Only ${\text{m}}_4$

As the lower thread has been cut, it causes change only in the force balance of ${\text{m}}_4$ which will cause acceleration only in ${\text{m}}_4$.