Question

A solid disc with radius R is is spinning. An object exerts a force F at the edge of the disc to slow down the disc. The disc slows down to rest in 2.0 seconds. How long would the disc take to stop if:

the mass of the disc doubled in s
the radius of the disc doubled in s
the force doubled in s

Answer 1

F=ma, so:

the mass of the disc doubled in s - it would take twice as long to stop

the radius of the disc doubled in s - it would take twice as long to stop

the force doubled in s - it would take half the time to stop