The quantity of heat Q that changes the temperature L1Tof a mass mof a substance isgiven by Q = cmt:T, where c is the specific heat capacity of the substance. Forexample, forH20,c=1caljg'C",Andfora change of phase, the quantity of heat Q that changes the phase of a mass m is Q = ml., where L is the heat of fusion or heat of vaporization of the substance. For example, for H20, the heat offusion is 80 cal/g (or 80 kcaljkg) and the heat of vaporization is 540 cal/g (or 540 kcaljkg). Use these relationships to determine the number of calories to change (a) 1 kg ofO°C ice to O°C ice water, (b) 1 kg ofO°C ice water to 1 kg of 100°C boiling water, (c) 1 kg of 100°C boiling water to 1 kg of 100°C steam, and (d) 1 kg ofO°C ice to 1 kg of 100°C steam.

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?

An object dropped from cliff falls with a constant acceleration of 10 metre per second square find its speed of two seconds after it was dropped

Emagnitude of the electrical force acting between a +2.4 ×  10–8  c charge and a +1.8 ×  10–6  c charge that are separated by 0.008 m is    n, rounded to the tenths place.