Two stepped bar is supported at both ends. At the join point of two segments, the force F is applied(downwards).Calculate reactive forces R1 and R3 at the supports. What is value of absolute maximal stress? Choose one answer nearest your result.

given= d1=10mm d2=20mm L1=20mm L2=10mm E=200GPa F=20kN

An air compression refrigeration system is to have an air pressure of 100 psia in the brine tank and an allowable air temperature increase of 60°f for standard vapor compression cycle temperatures of 77 f entering the expansion cylinder and 14 f entering the compression cylinder, calculate the coefficient of performance a. 2.5 b 3.3 c. 4.0 d. 5.0

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?

The proportional limit is always greater than the yield strength for a material. a)-trune b)- false