Astring that passes over a pulley has a 300 kg mass attached to one end and a 450 kg mass attached to the other end. the pulley, which is a disk of radius 10 cm, has friction in its axle. what is the magnitude of the frictional torque that must be exerted by the axle if the system is to be in static equilibrium?

State the right hand rule of the direction of magnetic field in a conductor carrying current

An engineer designs a roller coaster so that a car travels horizontally for 162 ft, then climbs 127 ft at an angle of 31.0° above the horizontal. it then moves 127 ft at an angle of 46.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.