Athin-walled, hollow sphere of mass m and radius r is free to rotate around a vertical shaft that passes through the center of the sphere. initially, the sphere is at rest. a small ball of clay of the same mass m moving horizontally at speed v grazes the surface of the sphere at its equator. after grazing the surface, the ball of clay is moving at speed v/2. what is the angular momentum of the ball of clay about the shaft before it grazes the surface? after it grazes the surface?

initial angular momentum is given as

final angular momentum is given as

Explanation:

Angular momentum of the ball about the axis of the thin walled sphere is given as

here we know that

before it grazes the surface the speed is "v" while after grazing the surface its speed is "v/2"

So we have

initial angular momentum is given as

final angular momentum is given as

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force