PLEASE I NEEEd help again. 4.Research: Some sports cars are designed with rear spoiler to make the car more stable when turning, accelerating, and braking.
a. Use the Internet or your local library to find an illustration of a spoiler to share with your class.
b. Does the spoiler increase or decrease friction between the rear tires and the road?
c. Some small hybrid cars and sport utility vehicles also have spoilers. What is their purpose? Is it the same or different from the spoiler on a sports car?

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?