Two insulated current-carrying wires (wire 1 and wire 2) are bound together with wire ties to form a two-wire unit. the wires are 2.83 m long and are stretched out horizontally parallel to each other. wire 1 carries a current of i1 = 8.00 a and the other wire carries a current i2 in the opposite direction. the two-wire unit is placed in a uniform magnetic field of magnitude 0.400 t such that the angle between the direction of i1 and the magnetic field is 71.0°. while we don't know the current in wire 2, we do know that it is smaller than the current in wire 1. if the magnitude of the net force experienced by the two-wire unit is 3.50 n, determine the current in wire 2.

There is a theory that indicates that dinosaurs became extinct when about 65 million years ago, a large asteroid hit the earth surface. dust caused by this collision blocked the sunlight reaching the earth's surface and many forms of life became extinct due to the cold. fearing this threat, how large the radius of an asteroid should you be looking for if the dangerous asteroid size is approximately the same as the one that killed the dinosaurs? available data suggests that about 18% of that asteroid's mass ended up as a dust spread evenly over earth after eventually settling out of the upper atmosphere. about 0.0180 g/cm^2 of dust, which is chemically different than the earth's rock, covered the earth's surface. typical asteroids have a density of about 1.9 g/cm^3. now that we know the size of the asteroid, how much energy was released during impact, assuming all of it was just the kinetic energy of the asteroid right before the impact?

An athlete is holding 24 lb of weights at a height of 6 inches above the stack as shown. to lower the weights, she applies a constant force of 5 lb to the handle. determine the velocity of the weights immediately before they hit the stack.

On a mild saturday morning while people are working inside, the furnace keeps the temperature inside the building at 23degreesc. at noon the furnace is turned off, and the people go home. the temperature outside is a constant 16degreesc for the rest of the afternoon. if the time constant for the building is 3 hr, when will the temperature inside the building reach 18degreesc? if some windows are left open and the time constant drops to 2 hr, when will the temperature inside reach 18degreesc?