Geologists use the Mohs Harness Scale (aka the Scratch Test) to determine the hardness of a mineral.
For more info, check out http://geology.com/minerals/mohs-hardness-scale.shtml
Answer:
Explanation:
The strength of the gravitational field at the surface of a planet is given by
(1)
where
G is the gravitational constant
M is the mass of the planet
R is the radius of the planet
For the Earth:
For the unknown planet,
Substituting into the eq.(1), we find the gravitational acceleration of planet X relative to that of the Earth:
And substituting g = 9.8 m/s^2,
Answer: The correct answer is : From the period-luminosity relation for Cepheids, he was able to determine the distance to Andromeda and show that it was far outside the Milky Way Galaxy.
Explanation: Hubble's law says that the recession velocity of a galaxy is directly proportional to its distance from us. Hubble measured the distance to the Andromeda galaxy by applying the period-luminosity relationship to Cepheid.
Answer:
Natalie says that all things with mass have a gravitational field, but the force is very weak and cannot be perceived around small objects.
Explanation:
The force due to gravity is proportional to the mass of the object and inversely proportional to the square of the distance between objects. The Earth is so massive that the force due to its gravity is much greater than the force between objects on the counter.
If there were no friction, the objects might move toward each other, depending on what other masses were near them tending to cause them to move in other directions.
Natalie's explanation is about the best.
__
<em>Additional comment</em>
The universal gravitational constant was determined by Henry Cavendish in the late 18th century using lead balls weighing 1.6 pounds and 348 pounds. His experiment was enclosed in a large wooden box to minimize outside effects. While these masses are somewhat greater than those of a glue bottle and stapler, the experiment shows the force of gravity between "small" objects <em>can</em> be measured.
Answer:
meteorite is a piece of interplanetary debris that lives its fiery drops during a through the earth's atmosphere and strikes the surface of the earth.
Explanation:
the meteorites which are most useful for the determination of the age of the solar system are the primitive meteorites. they consist light of colored or grey silicates mixed with metallic grains. the parent bodies of these meteorites are also mostly believed to be pieces asteriods left after they formed in the solar system.
