Auniform-density 7 kg disk of radius 0.21 m is mounted on a nearly frictionless axle. initially it is not spinning. a string is wrapped tightly around the disk, and you pull on the string with a constant force of 44 n through a distance of 0.9 m. now what is the angular speed?

Explanation:

Here we can use energy conservation

As per energy conservation conditions we know that work done by external source is converted into kinetic energy of the disc

Now we have

now we know that work done is product of force and displacement

so here we have

now for moment of inertia of the disc we will have

now from above equation we will have

unlike poles attract