Question

Two bodies of mass 3 kg and 4 kg are suspended at the ends of massless string passing over a frictionless pulley. The acceleration of the system is $\left( g = 9.8 m / s ^ { 2 } \right)$

• A. $4.9 m / s ^ { 2 }$
• B. $2.45 m / \mathrm { s } ^ { 2 }$
• C. $1.4 m / s ^ { 2 }$
• D. $9.5 m / s ^ { 2 }$

Answer 1

Answer: (C)

$1.4 m / s ^ { 2 }$

Answer 2

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

$= \frac { 4 - 3 } { 4 + 3 } \times 9.8 = \frac { 9.8 } { 7 } = 1.4 \mathrm {~m} / \mathrm { sec } ^ { 2 }$