Question

Two masses 2 kg and 3 kg are attached to the end of the string passed over a pulley fixed at the top. The tension and acceleration are

• A. $\frac { 7 g } { 8 } ; \frac { g } { 8 }$
• B. $\frac { 21 g } { 8 } ; \frac { g } { 8 }$
• C. $\frac { 21 g } { 8 } ; \frac { g } { 5 }$
• D. $\frac { 12 g } { 5 } ; \frac { g } { 5 }$

Answer 1

Answer: (D)

$\frac { 12 g } { 5 } ; \frac { g } { 5 }$

Answer 2

$T = \frac { 2 m _ { 1 } m _ { 2 } } { m _ { 1 } + m _ { 2 } } g = \frac { 2 \times 2 \times 3 } { 2 + 3 } g = \frac { 12 } { 5 } g$

$a = \left( \frac { m _ { 2 } - m _ { 1 } } { m _ { 1 } + m _ { 2 } } \right) g = \left( \frac { 3 - 2 } { 3 + 2 } \right) g = \frac { g } { 5 }$