Two children having a disagreement pull on a 50n sled in opposite directions. one pulls with a force of 300n east, the other with a force of 220n west. a frictional force of 30n exists between the sled and the surface. draw a free body diagram showing all the forces acting on the sled, and determine the net force on the sled

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.