Stepped bar designed from two joined elements is loaded by single compressive force F applied at free end. Calculate minimal longitudinal strain and choose one right answer the nearest to your result. Data: d1=10 mm, d2=14.141 mm, L1=20 mm, L2=40 mm, F=10 kN, E=200 GPa.

An inventor claims to have developed a reversed heat engine (ie. a heat pump) which is able to deliver 10 kj heat into the room at 20°c from outside ambient temperature of -10°c by consuming only 2 kj electricity in winter. this claim is a)-impossible b)-possible only if the heat pump is ideal c)-practically possible d)-unable to be assessed as it depends on the working fluid used in the heat pump.

Asharp-edged orifice is placed in a 10-in-diameter pipe carrying ammonia. if the volume flow rate is 25 gal/min, calculate the deflection of a water manometer (a) if the orifice diameter is 1.0 in and (b) if the orifice diameter is 7.0 in. the ammonia has a specific gravity of 0.83 and a dynamic viscosity of 2.5 x 10-6 lb s/t2

The inner surface of a 0.25m thick brick wall of a furnace is kept at 810ºc, when the outside surrounding air is at 22ºc. the convective heat transfer coefficient of the outer surface is 12 w/m2k and the thermal conductivity of the brick is 0.865 w/mk.neglect the convective resistance for the inner side of the furnace and assume that the problem is steady state and thermal radiation is neglected. (a)-sketch the system and calculate the rate of heat loss per unit wall area. (b)-calculate the temperature of the outer wall surface.