Aclever engineer designs a "sprong" that obeys the force law fx=-q(x-xe )3, where xe is the equilibrium position of the end of the sprong and q is the sprong constant. for simplicity well let xe=0 then fx=-qx3.
a) what are the units of q?
b) draw a graph of fx vs. x.
c) find an expression for the potential energy of a stretched or compressed spring.
d) a sprong-loaded toy gun shoots a 20g plastic ball. what is the launch speed if the spring constant is 40,000, with the units you found in part a, and the spring is compressed 10 cm? assume the barrel is frictonless.

What is the internal energy of 4.00 mol of diatomic nitrogen gas n2 at 455k

Time remainin52: 42the chart shows data for a moving object.which conclusion is best supported by the information inthe chart? time (s)velocity (m/s

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?