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?

You are your friend move a new refrigerator into his kitchen. you apply a horizontal force of 252 n in the negative x direction to try and move the 56 kg refrigerator. the coefficient of static friction is 0.61. (a) how much static frictional force does the floor exert on the refrigerator? give both magnitude (in n) and direction. magnitude n direction (b) what maximum force (in n) do you need to apply before the refrigerator starts to move?