Afield test is used to measure the density of crude oil recovered during a fracking*operation. the crude oil recovered is mixed with brine. the oil and brine mixture are placed in an open tank and allowed to separate. after separation, a 1.0-m layer of oil floats on top of 0.55 m of brine. the density of the brine is 1030 kg/m3and the pressure at the bottom of the tank is 14 kpa gage. find the density of the oil.

Ahot-air balloonist, rising vertically with a constant speed of 5.00 m/s releases a sandbag at the instant the balloon is 40.0 m above the ground. after it is released, the sandbag encounters no appreciable air drag. compute the velocity of the sandbag at 0.250 s after its release.

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.