Universal Law of Gravitation

You will have 2 days to complete this assignment.
Please carefully watch the next video to better understand the relationship of the variables in the Fg formula!

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Force of Gravity

Multiple Choice

In the video, what is the formula $$Fg=\frac{Gm_1m_{2\text{}}}{r^2}$$ called?

• Force of gravity

• Law of Universal Gravitation

• Force Formula

• Gravity

Multiple Choice

True or False: Newton created the Law of Universal Gravitation without knowing what G is.

• True

• False

Multiple Choice

What is G?

• 6.7 x 10 ¹¹

• 6.67 x 10^-11

• 8.7 x 10 ¹²

• 9.8 x 10 ^-11

Multiple Choice

What part of the force formula ( F = m x a) can be replaced with g for gravity?

• the F can become a g

• the a can become a g

• the m can become a g

• none of them

Multiple Choice

Why can the a in F=m x a become a g?

• a and g are both types of acceleration and use the same units

• a and g were both created by Newton

• They can't. It's a conspiracy theory

• a can by multiplied by g to get G

Multiple Choice

True or False: F=m x a is the same as F=m x g

• True

• False

CHECKPOINT

It is important to understand that F=ma and F=mg are related. Both acceleration and gravity use the same units and represent that same type of motion.

Multiple Choice

Considering the relationship between the two Force formulas, what does it mean when we say acceleration due to gravity?

• it's a type of speed

• it explains the velocity of earth's forces

• it's the acceleration of an object affected by the force of gravity

• it's just a phrase we say to say for- what goes up , must come down.

Multiple Choice

When referring to or calculating scenarios that involve Earth, what do we use for the "g" in F=mg?

• 6.67 x 10^-11

• 9.8

• the acceleration of the object

• it will be given in the equation

Multiple Select

Consider the formula for the Law of Universal Gravitation and the explanation in the clip. The video explained that "g" in F=mg can be derived from the Law of Universal Gravitation. Select all of the variables that can be used to calculate the "g":

• G

• r²

• m₁

• g

Multiple Choice

When you consider the Law of Universal Gravitation for any scenario on Earth, Gm₁/r² will always be equal to -

• 9.8m/s²

• 6.67 x 10^-11

Multiple Select

We know that all the variables on the right side of the equation will be 9.8m/s² if we are on Earth. Which variables will change if we were calculating a scenario on Mars? (select all that apply)

• g

• G

• M

• r

Multiple Choice

If "g" is equal to these 3 variables, where does the "m" come from in the formula F= m x g?

• That's the second m or m₂ that is not used in the Law of Universal Gravitation formula

• The "m" is mass of Earth

• it's just assumed

• It comes from the rainbow bridge to Asgard and we don't question those things.

• understand that F=ma, F=mg, the universal law of gravitation formula are related

• know how to derive 9.8 m/s² from this formula

• know that GM/r² is always the same when on Earth

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When we see this formula, we should

Try this out:

1. click to create a planet

2. hold the click down to make bigger planets

3. While holding down the click move the mouse in any direction to send the planet into motion

4. move planets closer and farther together of different sizes

Use the next simulation to answer the questions that follows. You may want to open the simulation on a seperate tab to go back and forth.

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Open Ended

What happens when a small planet passes by a larger planet?

Open Ended

How is it possible that a planet's direction of motion can change?

Open Ended

What happens if 2 large planets collide?

Open Ended

What happens if 2 small planets collide?

Open Ended

Place a large planet next to a small planet with no motion. Describe what happens to the small planet.