Question

A load of mass $M=100kg$ is supported is a vertical plane by a string and pulleys. If the free end $A$ of the string is pulled vertically downward with an acceleration $a=2m/s^2$

• A. $500N$
• B. $550N$
• C. $600N$
• D. $1000N$

Answer 1

The correct option is B $550N$

If end A moves, with acc. $a_1=2m/s^2$ then end B moves up with acc. $a_2=\frac{a_1}{2}=1m/s^2$

Now, equating forces,

$\Rightarrow 2T-Mg=M{a}_2$

$\Rightarrow 2T=M(g+a_2)$

$\Rightarrow T=\frac{100}{2}(10+1)$

$\Rightarrow T=550N$

Hence, the answer is $550N.$