A spinning disc with a mass of 2.5kg and a radius of 0.80m is rotating with an angular velocity of 1.5 rad/s. A ball of clay with unknown mass is dropped onto the disk and sticks to the very edge causing the angular velocity of the disk to slow to 1.13 rad/s. What is the mass of the ball of clay

To protect all four receptacles on a branch circuit that surrounds a swimming pool, you would install which of the following configurations? a. gfci feed-through receptacle at the end of the load's circuit b. gfci-terminated receptacle at the beginning of the load's circuit c. gfci feed-through receptacle at the beginning of the load's circuit and the other receptacles connected to the load side of that receptacle d. gfci-terminated receptacle at each end of the load's circuit

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?

Two 1.20-m nonconducting wires meet at a right angle. one segment carries + 2.50 µc of charge distributed uniformly along its length, and the other carries - 2.50 µc distributed uniformly along it, as shown in fig. 21.50. ( a. find the magnitude and direction of the electric field these wires produce at point p, which is 60.0 cm from each wire. ( b. if an electron is released at p, what are the magnitude and direction of the net force that these wires exert on it?