Dos cajas conectadas por una cuerda de masa insignificante se encuentran en una superficie horizontal. La caja A tiene masa m, y la caja B tiene masa mg. El coeficiente de fricción cinética entre cada caja y la superficie es µk. Las cajas son empujadas hacia la derecha a una velocidad constante de 3.20 cm / s por una fuerza horizontal F. En términos de m, mg yu, calcule (a) la magnitud de la fuerza F y (b) la tensión en la cuerda que conecta los bloques. Incluya los diagramas de diagrama de cuerpo libre que utilizó para determinar cada respuesta.

The law of conservation of energy states that energy cannot be created or , energy can be from one substance to another. the first blank is ' destroyed ' and for the second blank is ' transferred '

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?

What object a collides with object b and bounces back its final momentum is?