1. A mass of 50g is applied to a spring which stretches by 17mm. What is the spring constant? 2. How much energy does the spring in Q1 above store?
3. A catapult with a spring constant of 500N/m is stretched 30cm. How fast can it shoot an arrow with a mass of 50g?

Suppose an objects initial velocity is 10m/s and it’s final velocity is 4 m/s. mass is constant. what can best be concluded about the object based in the work-energy theorem

Which transition by an electron will release the greatest amount of energy? oa ob oc od

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?