Water (constant density) is to be pumped up a hill (gravity = (0,0,−g)) through a pipe which tapers from an area a1 at the low point to the smaller area a2 at a point a vertical distance l higher. what is the pressure p1 at the bottom, needed to pump at a volume rate q if the pressure at the top is the atmospheric value p0? (express in terms of the given quantities. assuming inviscid steady flow, use bernoulli’s theorem with gravity and conservation of mass. assume that the flow velocity is uniform across the tube in computing fluid flux and pressure.)

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

Which statement best describes copper? a. it has a low resistance and prevents charges from moving freely. b it has a high resistance and allows charges to move freely. c. it has a high resistance and prevents charges from moving freely. d. it has a low resistance and allows charges to move freely

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)