An object with a mass of 68.0 kg is pulled up an inclined surface by an attached chain, which is driven by a motor. The object moves a distance of 90.0 m along the surface at a constant speed of 1.5 m/s. The surface is inclined at an angle of 30.0° with the horizontal. Assume friction is negligible.   (a) How much work (in kJ) is required to pull the object up the incline?   (b) What power (expressed in hp) must a motor have to perform this task?

A sledge loaded with bricks has a total mass of 18.8 kg and is pulled at constant speed by a rope inclined at 19.0° above the horizontal. The sledge moves a distance of 20.5 m on a horizontal surface. The coefficient of kinetic friction between the sledge and surface is 0.500. (a) What is the tension in the rope? N (b) How much work is done by the rope on the sledge? kJ (c) What is the mechanical energy lost due to friction? k]

A skier of mass 77 kg is pulled up a slope by a motor-driven cable. (a) How much work is required to pull hìm 45 m up a 30° slope (assumed frictionless) at a constant speed of 1.9 m/s? kJ (b) What power (expressed in hp) must a motor have to perform this task? hp

The figure shows three forces applied to a trunk that moves leftward by 3.23 m over a frictionless floor. The force magnitudes are F1 = 4.70 N, F2 = 8.63 N, and F3 = 3.16 N, and the indicated angle is 0 = 60°. (a) During the displacement, what is the net work done on the trunk by the three applied forces, the gravitational force, and the normal force? (b) Is there a net transfer of energy to or from the trunk? (c) Does the kinetic energy of the trunk increase or decrease? (a) Number i Units (b) (c) >

What average mechanical power (in W) must a 61.5 kg mountain climber generate to climb to the summit of a hill of height 405 m in 46.0 min? Note: Due to inefficiencies in converting chemical energy to mechanical energy, the amount calculated here is only a fraction of the power that must be produced by the climber's body.

The loaded cab of an elevator has a mass of 4.20 x 10³ kg and moves 242. m up the shaft in 17.0 s at constant speed. At what average rate does the force from the cable do work on the cab?

A sledge loaded with bricks has a total mass of 18.1 kg and is pulled at constant speed by a rope inclined at 20.5° above the horizontal. The sledge moves a distance of 19.0 m on a horizontal surface. The coefficient of kinetic friction between the sledge and surface is 0.500. (a) What is the tension in the rope?N(b) How much work is done by the rope on the sledge?kJ(c) What is the mechanical energy lost due to friction?kJ