Acceleration = vf-vi /t
10-22/3=2.6m/s^2
Answer : Radius of Earth is 6,340 Km.
Explanation
It is given that,
Tangential velocity of Earth at the equator, v = 465 m/s
Centripetal acceleration at the equation is, 
We know that the relation between centripetal acceleration and tangential velocity is :
..........(1)
Where,
v is tangential velocity
r is the radius
Putting all values in equation (1)


or

The Earth's radius is 6,340 Km. Hence, this is the required solution.
Answer:
Part a)

Part b)

Explanation:
Part a)
Moment of inertia of the core of the ball



now the moment of inertia for thin shell



now total inertia of the ball is given as


Part b)
Moment of inertia of uniform ball of mass 3.2 kg


