Question

Three blocks A, B, C and attached by means of mass less strings as shown. Tension in the string connecting B, C is $30N$, mass of A, B are $3kg,5kg$. Find the mass of the block C and tension in the string connecting A, B.

Answer 1

$40-30=ma$

$ma=10$

$30=a\times (3+5)$

$\therefore a=\frac{30}{8}=\frac{15}{4}m/s^2$

$ma=10$

$m=\frac{10}{a}=\frac{10\times 4}{15}=\frac{8}{3}kg$

Now, $T=3a=3\times \frac{15}{4}=\frac{45}{4}N$