Question

A block A of mass 7 kg is placed on a frictionless table. A thread tied to it passes over a frictionless pulley and carries a body B of mass 3 kg at the other end. The acceleration of the system is (given g = 10 $\left. m s ^ { - 2 } \right)$

• A. $100 \mathrm {~ms} ^ { - 2 }$
• B. $3 m s ^ { - 2 }$
• C. $10 \mathrm {~ms} ^ { - 2 }$
• D. $30 \mathrm {~ms} ^ { - 2 }$

Answer 1

Answer: (B)

$3 m s ^ { - 2 }$

Answer 2

$a = \left( \frac { m _ { 2 } } { m _ { 1 } + m _ { 2 } } \right) g$ $= \left( \frac { 3 } { 7 + 3 } \right) 10 = 3 \mathrm {~m} / \mathrm { s } ^ { 2 }$