A 5 – foot ladder is placed against a vertical wall. Suppose that the bottom of the ladder slides away from the wall at a rate of 2 ft/sec. How fast is the top of the ladder sliding down the wall when the bottom of ladder is 4 feet away from the wall?

Why do astronauts in the space shuttle weigh less?

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.

Abowling ball rolling down the lane toward the pins has gravitational potential energy. a. no b. a lot of c. a little