Question 6: Laws of Motion

Question

In the figure, blocks A and B of
masses 2m and m are connected
with a string and system is hanged
vertically with the help of a spring.
Spring has negligible mass. Find
out magnitude of acceleration of
masses 2m and m just after the
instant when the string is cut

Accepted Answer

When the system is in equilibrium, then the
spring force is 3 mg. When the string is cut, then
net force on block A
$$=3mg-2mg=mg$$
Hence, acceleration of block A at that instant
$$a=\frac{	ext { force on block } A}{	ext { mass of block } A}=\frac{m g}{2 m}=\frac{g}{2}$$
When string is cut, then block $$B$$ falls freely with an acceleration equal to $$g$$.

Answer

$$g, g$$

Answer

$$g, \frac{g}{2}$$

Answer

$$\frac{g}{2}, g$$

Answer

$$\frac{g}{2}, \frac{g}{2}$$

Laws of Motion

In the figure, blocks A and B of masses 2m and m are connected with a string and system is hanged vertically with the help of a spring. Spring has negligible mass. Find out magnitude of acceleration of masses 2m and m just after the instant when the string is cut

Choose the correct answer: