A board of uniform size and composition sits horizontally on a support positioned under its center. The mass of the board is unknown. If there is a 20.0 kg mass is on the right hand end of the board what is the constant of the spring holding the other end of the board if it is stretched .500 m past its equilibrium position?

Which type of circuit is becoming more common in residential electrical design and construction? a. hazardous-area circuit b. three-phase circuit c. 480-volt circuit d. communication circuit

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.

Atypical jetliner lands at a speed of 146 mi/h and decelerates at the rate of (10.4 mi/h)/s. if the jetliner travels at a constant speed of 146 mi/h for 1.5 s after landing before applying the brakes, what is the total displacement of the jetliner between touchdown on the runway and coming to rest?