A boat passes under a bridge. At the instant the boat passes from under the bridge an arrow is fired horizontally, striking the boat after 0.0128 hrs. The boat traveled 0.072 km in the same time the arrow was in the air. (Assume a = -10 m/s2) Calculate the boat’s velocity in m/s. Show all conversions with cancellations (3 pts; 1 pt formula, 1 pt setup with cancellations, 1 pt answer)

In m/s, what must the horizontal velocity of the arrow be in order to strike the boat as stated in the prompt? Justify your answer. (1 pt)

What is the initial vertical velocity of the arrow? Justify your answer. (1 pt)

How far does the arrow fall? (3 pts; 1 pt formula, 1 pt substitution, 1pt answer)

What is the vertical velocity of the arrow just before it strikes the ground? (3 pts; 1 pt formula, 1 pt substitution, 1 pt answer)

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?

What is the measure of a change in an objects velocity?

The charge on an electron is 1.60218 × 10−19 c and its mass is 9.10939 × 10−31 kg. how strong a magnetic field must be experienced by the electron if its path is a circle of radius 5.5 cm? answer in units of t.