Asealed pressure cooker allows steam to escape only through an opening in the lid. a separate metal object, called a petcock, sits on top of the opening and prevents steam from leaving until the pressure within the cooker overcomes the weight of the petcock. the petcock and the periodic escape of steam prevents the dangerous buildup of pressure and keeps the pressure inside the cooker above atmospheric pressure. determine the mass of the petcock of a pressure cooker whose operational pressure is 100 kpa gage and has a round opening 4 mm in diameter. assume atmospheric pressure is 101 kpa.

Two technicians are discussing a resistance measurement between the can-h and can-l wires. technician a says this measurement should be done with the ignition switch in the "run" position. technician b states that a measurement of 0 ohms indicates an open in the network. which technician is correct?

Suppose that two tanks, 1 and 2, each with a large opening at the top, contain different liquids. a small hole is made in the side of each tank at the same depth 1.57 m below the liquid surface, but the hole in tank 2 has 2.49 times the cross-sectional area of the hole in tank 1. (a) what is the ratio ρ1/ρ2 of the densities of the liquids if the mass flow rate is the same for the two holes? (b) what is the ratio rv1/rv2 of the volume flow rates from the two tanks? (c) at one instant, the liquid in tank 1 is 14.9 cm above the hole. if the tanks are to have equal volume flow rates, what height above the hole must the liquid in tank 2 be just then?

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2