Space pilot mavis zips past stanley at a constant speed relative to him of 0.800c. mavis and stanley start timers at zero when the front of mavis ship is directly above stanley. when mavis reads 5.00 s on her timer, she turns on a bright light under the front of her spaceship. (a) use the lorentz coordinate transformations to calculate x and tas measured by stanley for the event of turning the light. (b) use the time dilation formula to calculate the time interval between the two events (the front of the spaceship passing overhead and turning on the light) as measured by stanley. compare to the value of t you calculated in part (a). (c) multiply the time interval by mavis speed, both as measured by stanley, to calculate the distance she has traveled as measured by him when the light turns on. compare to the value of x you calculated in part (a).

The speed of sound in ice, water, and steam is shown. what best explains the speed of sound in different states of matter? sound travels fastest in ice because energy is easier to transfer when the molecules are close together. sound travels slowest in steam because the sound has to move around the gas molecules that are far apart. sound travels fastest in ice because the temperature of solids is always greater, so the heat transfers the sound energy. sound travels slowest in steam because the pressure is so great the sound cannot travel though the steam particles.

Oxygen and hydrogen gas are at the same temperature t.what is the ratio of kinetic energies of oxygen molecule and hydrogen molecule if oxygen is 16 times heavier than hydrogen.

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?