Apulley 12 cm in diameter is free to rotate about a horizontal axle. a 220-g mass and a 470-g mass are tied to either end of a massless string, and the string is hung over the pulley. assuming the string doesn’t slip, what torque must be applied to keep the pulley?

0.147 N-m

Explanation:

Given

Diameter of Pulley

radius

mass of first object

mass of second object

Now both masses will exert a torque a on Pulley

Torque due to first Pulley

Torque due to second mass on Pulley

Total Torque by masses

so we need to apply a torque of magnitude 0.147 N-m opposite to the direction of  

d) the number of neutrons plus the number of protons