A refrigeration system was checked for leaks. The system temperature and surroundings were 75°F when the system was charged with nitrogen to 100 psig. The temperature then dropped to 50°F. What should the pressure be if no nitrogen has escaped? A) 9 psig
B) 94 psig
C) 100 psig
D) 90 psig

Acertain flow of air (at stp) has a velocity distribution given by v i (in ft/s). if this flow is going through a 4 ft square area in the yz-plane (centered at the origin), what is the mass flow rate (in lbm/s)?

Avertical steel rod of length 2.0 m and diameter 25 mm is rigidly fixed at its upper end and has a flange at its lower, free, end. what will be the maximum stress produced in the rod when a load of 20 kn is applied, (a) gradually to the lower end, (b) suddenly to the lower end, (c) by a collar falling from a height of 50 mm on to the flange?

Cold water (cp=4180j/kg k) leadıng to a shower enters a thin-walled double-pipe heat transfer at 15c at a rate of 0.25kg/s and is heated to 45c by hot water (cp=4190j/kg k) that enters at 100c at the rate of 3kg/s. if the overall heat transfer coefficient is 950w /m2 k , determıne the rate of heat transfer and the heat transfer surface area of the heat exchanger using e - ntu method