An antique rifle fires 9 mm bullets such that as they travel down the barrel of the rifle their speed is given by v = (−4.60 ✕ 107)t2 + (2.55 ✕ 105)t, where v is in meters per second and t is in seconds. The acceleration of the bullet just as it leaves the barrel is zero. (a) Determine the acceleration (in m/s2) and position (in m) of the bullet as a function of time when the bullet is in the barrel. (Use the following as necessary: t. Round all numerical coefficients to at least three significant figures. Do not include units in your answers. Assume that the position of the bullet at t = 0 is zero.)

Which of the following elements is in the same period as phosphorus? a. carbon c. nitrogen b. magnesium d. oxygen select the best answer from the choices provided a b c d

Standing side by side ,you and a friend step off a bridge at different times and fall for 1.6s to the water below.your friend goes first,and you follow after he has dropped a distance of 2.0m.when your friend hits the water,is the seperation between the two of you 2.0m or more than 2.0m? verify your answer with a calculation.

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?