How many fundamental forces are there in creation?

Four: Gravitational force, electromagnetic force, weak force and strong force.

Describe "Gravitational Force"

Gravitational force is the force that attracts any two object that have mass.

Gravitational force is always attractive.

According to Newton's Universal Law of Gravitation, what are three principles used in calculating the strength of the gravitational force between two objects?

1. All objects with mass are attracted to one another by the gravitational force.

2. The gravitational force between two masses is directly proportional to the mass of each object.

3. The gravitational force between two masses is inversely proportional to the square of the distance between two objects.

What is another way to say, "smaller by a factor of 6?"

"Smaller by a factor of 6" is the same as saying "divided by 6."

If a problem tells you that a result is "larger by a factor of 3," what does that mean?

"Larger by a factor of 3" is the same as mulitplying by 3.

Solve the following problem about gravitational force:

The gravitational force between two objects (mass₁ = 5 kg, mass₂ = 2 kg) is measured when the objects are 5 cm apart.  If the distance between them is increased to 10 cm, how does the new gravitational attraction compare to the first one that was measured?

Answer: The new gravitational force is 4 times smaller than the old one.

Explanation: The only difference is that the distance between the objects was multiplied by 2.  The gravitational force decreases when the distance between the objects increases.  It is decreased according to the the square of that increase. Thus, since the distance is multiplied by 2, the force is divided by 2² = 4. 

Is gravitational force a strong or weak force?

Very weak!

However, remember that as the mass of an object increases, gravitational force increases so a HUGE object has a formidable gravitational force.

Is the gravitational force of the sun attracting earth greater than or lesser than the gravitational force of the earth attracting the sun?

Trick Question!

Answer: The two forces are equal in strength and opposite in direction.

Define:

Centripetal Force

The force necessary to make an object move in a circle. 

It is directed perpendicular to the direction of the velocity of the object, which means it points to the center of the circle.

What is required for circular motion?

centripetal force

(Without centripetal force acting on it, the velocity of an object (which requires direction) will continue in a straight line.)

Define/Explain:

Centripetal Acceleration

Centripetal Acceleration is when centripetal force is exerted on an object which causes constant directional change (and therefore velocity change) even though the speed is constant.

What are the three principles regarding centripetal force we learned from experiment 11.1?

1. Circular motion requires centripetal force.

2. The larger the centripetal force, the faster an object travels in a circle of a given size.

3. At a given speed, the larger the centripetal force, the smaller the circle.

What is centrifugal force?

Non-existent! :)

Why does the earth travel around the sun?

Answer: The earth travels around the sun because the sun attracts the earth with its gravitational force which is perpendicular to the earth's velocity. 

Therefore, because of this centripetal force, the earth travels around the sun in an elliptical orbit.

Name the planets in our solar system in order.

Mercury

Venus

Earth

Mars

Jupiter

Saturn

Uranus

Neptune

(Not Pluto anymore! Poor Pluto.)

You can remember the order by saying: "My very educated mother just served us noodles."

Which planets are considered the inner planets in our solar system?

The outer planets are: Jupiter, Saturn, Uranus, and Neptune.

1. They are all outer planets.

2. They have similar compositions and those compositions are mostly gas.

3. They all have rings.

4. They are all very cold.

What is insolation?

Which planet receives more insolation: Mars or Saturn?

Insolation is energy from the sun.

Mars receives more insolation than Saturn does because the amount of insolation is entirely dependent on the planet's proximity to the sun.

Name the planets that have rings.

Saturn, Uranus, Jupiter and Neptune all have rings.

1. In outer space, an asteroid is, well, an asteroid. :)

2. If it is thrown out of its standard orbit and moves, toward a planet they become known as meteroids when they intersect a planet's orbit.

3. When meteroids actually hit a planet's atmosphere, they are called meteors.

4. The few small pieces that survive the intense heat of moving through the atmosphere are known as meteroites.

Thus: asteroid, meteroid, meteor, meteorites.

If a rock is found on earth and tests reveal that it fell from outer space, what should it be called?

A comet is an object in outer space made up mostly of dust grains, chunks of dirt and ice (which is comprised of frozen water, frozen carbon dioxide, frozen ammonia, and frozen farts. (I mean methane.)

The common nickname is "dirty snowballs."

What happens when a comet has sublimated?

What are the three parts of the comet called after sublimation?

When the comet gets close enough to the sun, the "dirty snowball" heats up enough for the frozen, solid material to change directly to gas without passing through the liquid phase.

After sublimation, the dust, dirt and ice that makes up the solid part of the comet is called the nucleus.  The fuzzy atmosphere around the comet is called the coma.

The coma emits light (glows) and the gases thereof usually form a long, glowing tail.

What are the three classifications of comets and why are they classified as such?

The classifications of comets are based on the period of the comet, or the amount of time it takes for the comet to orbit the sun.

The three classifications are:

1. Short-period comets which take less than 200 years to make an orbit;

2. Long-period comets which take more than 200 years (but less than 5,000 years) to orbit the sun -- and usually have orbits beyond Neptune;

3. Very long-period comets have orbits that take them to the edge of the solar system and require more than 5,000 years for a complete orbit.