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.

We will use a video to study faraday’s law of electromagnetic induction by analyzing the induction that occurs due a coil of copper wire sliding along an air track that passes through an external magnetic field. specifically, we will: examine some of the main principles behind faraday’s law. apply lenz’s law to determine the direction of the induced emf. take measurements of the induced emf from the voltmeter as the coil passes into and out of the external magnetic field. use the horizontal scale provided to determine the speed of the coil. calculate the magnetic field induced in the coil as it passes into and out of the external magnetic field.