Which statement best describes a difference between the trachea and the esophagus?
The trachea is a long, hollow tube, and the esophagus is a small, kidney-shaped organ
The trachea is part of the digestive system, and the esophagus is part of the respiratory system
The trachea delivers oxygen through the body, and the esophagus releases carbon dioxide
The trachea allows for the passage of air, and the esophagus allows for the passage of food

Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

An electric current in a wire will push or pull on a permanent magnet. which statement best explains how an electric current creates an electromagnetic force on another magnet?

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?