Suppose two stars are in an orbit with a period of 10 years, and each star has a mass of one solar mass. a) if the orbit is circular and has a maximum separation of 1" between the stars, how distant is the binary? b) explain qualitatively how you would determine that the orbit is circular if the trace of the orbit on the sky is 1" in the long direction and 0.1" in the short direction, and explain one other quantitative thing you know about the binary based on that ratio

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?

A100 kg running back runs at 5m/s into a stationary linebacker. it takes 0.5 for the running back to be completely stopped

What happens when a rubber rod is rubbed with a piece of fur?