Coherent light with lambda equals 644 n m illuminates on a double slit. The white screen is 6 cm from the slits. The two slits are spaced apart by 2,783 nm. Determine the distance on the screen between the 4th and the 2nd bright fringes above the central maximum.

Work out sian speed for the first 30 minutes of her journey. give your answer in km/h.

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?

A51 kg woman skis down a hill and her kinetic energy is 9.96e4 j. what is her speed?