Say you want to know the change in kinetic energy of a ball. you measure its mass, m, its intial velocity, v1, its final velocity, v2, and uncertainties on all of these values: om, op, and ou, respectively. the formula for the change in kinetic energy, ak, is given by ak = m(uz - ví). (a) first write oak in terms of įm, 01/2m, (vź – ví), and 0(13- (b) write 01/2m in terms of om (this should be very easy). (c) write (3-w) in terms of uź - ví), ví, vž, ? , and 0. (d) now write oz in terms of vi and ovi. (e) write uz in terms of v2 and 02 (you should be able to write this down without thinking based on your previous answer). (f) now put all your answers together and express oak in terms of m, 01, 02, 0m, oui, and ouz.

Which statement best describes how private industry decides where to spend the money on research and development

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?

An object weigh 40n in air ,weigh 20n when submerged in water,and 30n when submerged in a liquid of unknown liquid density.what is the density of unknown of liquid?