Au-tube is filled with water until the liquid level is 28cm above the bottom of the tube. an oil of specific gravity 0.78 is now poured into one arm of the u-tube until the level of the water in the other arm of the tube is 34 cm above the bottom of the tube. find the level of the oil-water and oil-air interfaces in the other arm of the tube.

Astudent pushes on a 20.0 kg box with a force of 50 n at an angle of 30° below the horizontal. the box accelerates at a rate of 0.5 m/s2 across a horizontal floor. what is the value of the normal force on the box? 200 n 243 n 156 n 225 n

An ideal otto cycle has a compression ratio of 8. at the beginning of the compression process, air is at 95 kpa and 27°c, and 750 kj/kg of heat is transferred to air during the constant-volume heat-addition process. assuming constant specific heats at room temperature, determine (a) the pressure and temperature at the end of the heat-addition process, (b) the net work output, (c) the thermal efficiency, and (d) the mean effective pressure for the cycle. (4390 kpa, 1730 k; 423 kj/kg; 56.4%; 534 kpa)

What is an electric motor? explain its operation. 2-3 sentence