Molecular Physics | Thermodynamics Answers

A sample of blood is placed in a centrifuge of radius 16.0 cm. The mass of a red blood cell is 3.0 ✕ 10⁻¹⁶ kg, and the magnitude of the force acting on it as it settles out of the plasma is 4.0 ✕ 10⁻¹¹ N. At how many revolutions per second should the centrifuge be operated?

__rev/s

(a) Find the magnitude of the gravitational force (in N) between a planet with mass 8.25 ✕ 10²⁴ kg and its moon, with mass 2.30 ✕ 10²² kg, if the average distance between their centers is 2.30 ✕ 10⁸ m.

 __N

(b) What is the moon's acceleration (in m/s²) toward the planet? (Enter the magnitude.)

 __m/s²

(c) What is the planet's acceleration (in m/s²) toward the moon? (Enter the magnitude.)

__ m/s²

A comet has a period of 80.8 years and moves in an elliptical orbit in which its perihelion (closest approach to the Sun) is 0.670 AU. Find the semimajor axis of the comet and an estimate of the comet's maximum distance from the Sun, both in astronomical units.

(a)

the semimajor axis of the comet (in AU)

 __AU

(b)

an estimate of the comet's maximum distance (in AU) from the Sun

 __AU

Asynchronous satellite, which always remains above the same point on a planet's equator, is put in a circular orbit around Uranus so that scientists can study a surface feature. Uranus rotates once every 17.2 h. Use the data of this table to find the altitude of the satellite.

__km

The dung beetle is known as one of the strongest animals for its size, often forming balls of dung up to 10 times their own mass and rolling them to locations where they can be buried and stored as food. A typical dung ball formed by the species K. nigroaeneus has a radius of 1.85 cm and is rolled by the beetle at 6.20 cm/s.

(a)

What is the rolling ball's angular speed (in rad/s)?

___ rad/s

(b)

How many full revolutions are required if the beetle rolls the ball a distance of 1.35 m?

___ rev