Three identical boxcars are coupled together and are moving at a constant speed of 28.0 on a level, frictionless track. they collide with another identical boxcar that is initially at rest and couple to it, so that the four cars roll on as a unit. friction is small enough to be neglected. part awhat is the speed of the four cars? part bwhat percentage of the kinetic energy of the boxcars is dissipated in the collision? part cwhat happened to this energy?

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.

What equation is used to calculate the weight of an object on a plant ?

What are some important factors to consider when choosing a warm-up before your workout?