A star is rotating with a period of 10.0 days. It collapses with no loss in mass to a white dwarf with a radius of .001 of its original radius.
a) What is its initial angular velocity?
b) What is its angular velocity after collapse?

Part a)

Initial angular speed of the star is

Part b)

Final angular speed of the star after it collapse is given as

Explanation:

Part a)

As we know that angular speed is given as

now we have

Part b)

As we know that star collapses due to its own force

So here we can say that angular momentum is conserved here

So we have

powerful computers now, not then

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27