Amachine pulls a 42 kg trunk 3.3 m up a 26o ramp at constant velocity, with the machine's force on the trunk directed parallel to the ramp. the coefficient of kinetic friction between the trunk and the ramp is 0.26. what are (a) the work done on the trunk by the machine's force and (b) the increase in thermal energy of the trunk and the ramp?

Aweight lifter raises a 1600 n barbell to a height of 2.0 meters. how much work was done? w = fd a) 30 joules b) 3000 joules c) 320 joules d) 3200 joules

Select all the correct answers. which three statements about electromagnetic radiation are true?

Ahair dryer is basically a duct in which a few layers of electric resistors are placed. a small fan pulls the air in and forces it through the resistors where it is heated. air enters a 1200 w hair dryer at 100 kpa and 22°c and leaves at 47°c. the cross-sectional area of the hair dryer at the exit is 60 cm2. neglecting the power consumed by the fan and the heat losses through the walls of the hair dryer, determine (a) the volume flow rate of air at the inlet and (b) the velocity of the air at the exit.