Dos policias de caminos que se encuentran en reposo repecto a la carretera estan separados por una distancia de 70 km. Pasa un coche por la pocision del primero, quien le avisa a su compañero por radio. Media hora despues, el coche pasa frente al segundo policía. Si el limite de rapidez para transitar por esa carretera es de 110 km/h, ¿puede saberse si el vehículo ha superado dicho limite¿

Certain bacteria (such as aquaspirillum magnetotacticum) tend to swim toward the earth’s geographic north pole because they contain tiny particles, called magnetosomes, that are sensitive to a magnetic field. if a transmission line carrying 100 a is laid underwater, at what range of distances would the magnetic field from this line be great enough to interfere with the migration of these bacteria? (assume that a field less than 5% of the earth’s field would have little effect on the bacteria. take the earth’s field to be 5.0 * 10-5 t, and ignore the effects of the seawater.)

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge

Because air contracts as it cools, the air pressure inside a freezer is typically lower than on the outside. why do ice cubes inside a freezer tend to shrink over time? the ice sublimes, and then the water vapor deposits as ice crystals on the sides of the freezer. the ice melts, and then the liquid freezes as ice crystals on the bottom of the freezer. the ice dissolves oxygen from the air, forming a denser crystalline matrix. the ice reacts chemically with carbon dioxide in the air, forming gaseous carbon compounds.