3. The magnetic field between the coils is given by: B = 520µ0 I (1/x1 + 1/x2) where xi =Ri [4 + (d/Ri) 2 ] 3/2 with Ri their radius and d their separation. a) From the above result the magnetic field between the coils can be written as B = kI for some constant k that depends on the geometry of the coils. Using your values for R1, R2, and d, calculate k. Attempt to estimate the uncertainty on k. k = b) If you were able to determine a non-zero coil current to offset the earth’s magnetic field in part 2, use the above result to determine the component of the room magnetic field BE along the coil axis. How does your estimate for BE compare with the horizontal Earth field component in Santa Monica BE ≈ 0.245 gauss?

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies. molten iron has a density of 7.0g/cm cubed. in its solid state, iron has a density of 8.0g/cm cubed.

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i. e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i. e. include the distance traveled to the first encounter)