If you double the radius, for a fixed angular velocity, the tangential velocity will: a. decrease by halfb. stay the samec. increase by a factor of twod. increase by a factor of four

C. Increase by a factor of two.

Explanation:

Lets take angular speed =

Initially radius = r m

The tangential velocity = v m/s

We know that

If the radius becomes double ,lets say r'

r'= 2 r

Then

The tangential velocity = v' m/s

v' = 2 v

Then we can say that velocity will become double.

Therefore the answer will be C.

C. Increase by a factor of two.

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.