Question

a) find acceleration,
b) Find tension in string?

Answer 1

From above figure $\left(1\right)$

$T=10a$ ...(1)

$500-T=20a$ ...(2)

From equation (1) and (2)

$a=\frac{500}{3}N$

$T=\frac{500}{3}N$

From above figure . $\left(2\right)$

$500-T=10a$ (1)

$T=20a$ (2)

From equation (1) and (2)

$500=30a$

$a=\frac{500}{3}m/s^2$

and

$T=\frac{1000}{3}N$