High‑speed ultracentrifuges are useful devices to sediment materials quickly or to separate materials. an ultracentrifuge spins a small tube in a circle of radius 13.1 cm at 5.0 rev/min. what is the centripetal force experienced by a sample that has a mass of 0.00310 kg?

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s.part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.

State the below theories and give the name of the writer of the theory 1. wave theory 2. quantum theory 3. corpuscular theory 4. electromagnetic theory