A60-kg man uses an electric chair to carry him up the stairs. if the chair has a mass of 200 kg, what power must a motor generate to transport the man and chair 5 m vertically in 10 seconds, assuming a constant velocity and ignoring all forces except gravity? 900 w 1300 w 400 w 1200 w

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

Ahorizontal force of 400.0 n is required to pull a 1760 n truck across the floor at a constant speed. find the coefficient of sliding friction.

What happens when the number of protons in an atom changes