Space vehicles traveling through earth's radiation belts can intercept a significant number of electrons. the resulting charge buildup can damage electronic components and disrupt operations. suppose a spherical metallic satellite 1.3 m in diameter accumulates 3.0 µc of charge in one orbital revolution. (a) find the resulting surface charge density. (b) calculate the magnitude of the electric field just outside the surface of the satellite, due to the surface charge.

Which example has gravitational potential energy? a.a horse slowing down from a run b.an apple about to fall from a tree branch c.a bicycle being pedaled down a horizontal path d.beaker sitting on the floor

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.

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?