A fluid is heated using a 30% efficient hot plate, rated to provide 235 watts [W] of input power. This device is used to heat 250-milliliters [mL] of a liquid in 30 minutes [min]. The liquid has a specific heat of 1.8 calories per gram degrees Celsius [cal/(g ℃)] and a specific gravity of 1.25. The initial temperature of the fluid is 65 degrees Fahrenheit [°F]. What is the final temperature of the fluid, in units of Celsius [oC]?

Search coils and credit cards. one practical way to measure magnetic field strength uses a small, closely wound coil called a search coil. the coil is initially held with its plane perpendicular to a magnetic field. the coil is then either quickly rotated a quarter-turn about a diameter or quickly pulled out of the field. (a) derive the equation relating the total charge q that flows through a search coil to the magnetic-field magnitude b. the search coil has n turns, each with area a, and the flux through the coil is decreased from its initial maximum value to zero in a time ∆t. the resistance of the coil is r, and the total charge is q = i∆t, where i is the average current induced by the change in flux. (b) in a credit card reader, the magnetic strip on the back of a credit card is rapidly “swiped” past a coil within the reader. explain, using the same ideas that underlie the operation of a search coil, how the reader can decode the information stored in the pattern of magnetization on the strip. (c) is it necessary that the credit card be “swiped” through the reader at exactly the right speed? why or why not?

The amount of heat required to change liquid water to vapor at its boiling temperature is 2256 kj/kg. the amount of heat required to change liquid mercury to its vapor state at its boiling temperature is 295 kj/kg. one kg of each substance is currently at its boiling point. how will the amount of thermal energy required to change each substance from a liquid to a gas differ?

Whithin which type of system is neither the total mass nor the total energy conserved ? a. open b. connected c. isolated d. closed