Answer:
0.72
Explanation:
= Time period of oscillation = 1.5 s
Angular frequency is given as

= Amplitude of oscillation = 40 cm = 0.40 m
= Coefficient of static friction = ?
= acceleration of the block
= mass of the block
Maximum acceleration of the block is given as

frictional force is given as

As per newton's second law

Answer: 1
Explanation:
Given
Tension is the string 
mass of object 
Tension is greater than the weight of the object i.e. elevator is moving upward
we can write
