Answer:
The mass of the another block is 60 kg.
Explanation:
Given that,
Mass of block M= 100 kg
Height = 1.0 m
Time = 0.90 s
Let the mass of the other block is m.
We need to calculate the acceleration of each block
Using equation of motion

Put the value into the formula



We need to calculate the mass of the other block
Using newton's second law
The net force of the block M

....(I)
The net force of the block m

Put the value of T from equation (I)



Put the value into the formula


Hence, The mass of the another block is 60 kg.