Acompass originally points north; at this location the horizontal component of the earth's magnetic field has a magnitude of 2e-5 t. a bar magnet is aligned east-west, pointing at the center of the compass. when the center of the magnet is 0.25 m from the center of the compass, the compass deflects 70 degrees. what is the magnetic dipole moment of the bar magnet?

Aspring has a relaxed length of 33 cm (0.33 m) and its spring stiffness is 6 n/m. you glue a 76 gram block (0.076 kg) to the top of the spring, and push the block down, compressing the spring so its total length is 15 cm. you make sure the block is at rest, then at time t=0 you quickly move your hand away. the block begins to move upward, because the upward force on the block by the spring is greater than the downward force on the block by the earth. calculate y vs. time for the block during a 0.09-second interval after you release the block, by applying the momentum principle in three steps each of 0.03-second duration.