Newton observed the action of a prism on white light and on red light. because he (did or did not) control the event, this investigation of light was ( a controlled experiment or a field study or an observational study or a simulation)

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

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)

Compare the horizontal displacement of the two balls as they travel to the ground. what do you observe?