An electron moving at 2.97×103 m/s in a 1.25 t magnetic field experiences a magnetic force of 1.40×10−16 n . what angle (in degrees) does the velocity of the electron make with the magnetic field? there are two possible answers. [hint: most calculators will only return the answer that falls in the first quadrant (0 - 90 degrees), but there is another angle in the second quadrant (90 - 180 degrees) that also satisfies the equation.]

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)