Answer:
Angular velocity, 
Explanation:
The mass of the skater, M = 74.0 kg
Mass of each arm,
( since it is 13% of the whole body and each arm is considered)

Mass of the trunk, 

Total moment of Inertia = (Moment of inertia of the arms) + (Moment of inertia of the trunks)


The final moment of inertia of the person:

According to the principle of conservation of angular momentum:

Answer:
a) iv. Displacement per unit time
b) ii. m/s2
c) this question is wrong
d) iv. m
Answer:
4. both blocks will both have the same amount of kinetic energy.
Explanation:
When the blocks are released free from the compression force, the spring exerts equal and opposite force on each block but the block with heavier (double) mass will attain slower ( half ) speed as compared to the lighter block according to the law of inertia. This works in synchronization to energy conservation.
Spring force is given as:

where:
length of compression in the spring
<u>We know kinetic energy is given by:</u>

Hence the kinetic energy of both the blocks is equal when they are released to move free.
F=MA
F is force
M is mass
A is acceleration
F=MA
F=(7.5 kg)(8.3 m/s^2)
F=62.25 N (newton- SI unit for force)
Hope this helps