An ultracentrifuge spins biological samples at very high speeds in order to separate their constituent microscopic components. one such instrument spins at 120,000 rpm, and the samples experience a centripetal acceleration of 6.6×10^6 m/s^2. what is the radius of the circle around which the samples travel?

4.2 cm

Explanation:

f = 120,000 rpm = 120,000 / 60 = 2000 rps

a = 6.6 x 10^6 m/s^2

a = rw^2

6.6 x 10^6 = r x (2 x 3.14 x 2000)^2

r = 0.042 m = 4.2 cm

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.

hi there!

your question asks at which segment does freezing occur.

since we're talking about water, the freezing point of water will be 32 degrees fahrenheit or below.

hope this ! ~