Two students are discussing the motion of the dart-block system at the instant it reaches height H. The students make the following statements: Student 1: The speed of the system at height H is zero. Since it is moving in a circular motion and centripetal acceleration is given by, the acceleration must also be zero. Student 2: The acceleration of the system at height H can’t be zero, or the system would not swing. The acceleration must be equal to g at height H.

Which underlined phrase or phrases, if either, are correct about student 1's statement? If neither phrase is correct, write "none."Read more on Sarthaks. com -

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?

The junction rule describes the conservation of which quantity? note that this rule applies only to circuits that are in a steady state.

How can you measure the amplitude of a longitudinal wave?