There are over a dozen good ones, starting today with:
Universal Law of Gravitation
Thanks to Newton's universal law, we can figure out the gravitational force between any two objects.
We may take it for granted now, but more than 300 years ago Sir Isaac Newton proposed a revolutionary idea: that any two objects, no matter their mass, exert gravitational force toward one another. This law is represented by an equation that many high schoolers encounter in physics class. It goes as follows:
F = G × [(m1m2)/r2]
F is the gravitational force between the two objects, measured in Newtons. M1 and m2 are the masses of the two objects, while r is the distance between them. G is the gravitational constant, a number currently calculated to be 6.672 × 10-11 N m2 kg-2 [source: Weisstein].
The benefit of the universal law of gravitation is that it allows us to calculate the gravitational pull between any two objects. This ability is especially useful when scientists are, say, planning to put a satellite in orbit or charting the course of the moon.
Here are some good questions about gravity for, hopefully more than Carl.
1 . Suppose that two objects attract each other with a force of 16 units (like 16 N or 16 lb). If the distance between the two objects is doubled, what is the new force of attraction between the two objects?
2. If you wanted to make a profit in buying gold by weight at one altitude and selling it at another altitude for the same price per weight, should you buy or sell at the higher altitude location?
3. What would happen to your weight if the mass of the Earth somehow increased by 10%?
4. The planet Jupiter is more than 300 times as massive as Earth, so it might seem that a body on the surface of Jupiter would weigh 300 times as much as on Earth. But it so happens a body would scarcely weigh three times as much on the surface of Jupiter as it would on the surface of the Earth. Explain why this is so.
metmike
This is all great stuff but I dont thin k I am capable of that kind of learning anymore-as with me trying to learn
a language.
Must have lost a gene or two in my old age.
Maybe just the desire
John
John,
From what I can tell, you seem pretty intelligent to me................you're here aren't you(-:
Stick around and maybe learn some physics. I apologize for getting too technical on it for non physics folks but it isn't going to hurt anybody to present it...........and I'm betting that everyone will get some of it.
And I do appreciate your honesty and that there are other things in most peoples lives that inspire them besides the laws of physics.
Actually John, you raised a good point.
Physics isn't for everybody.
Climate change isn't for everybody.
History isn't for everybody.
Notable quotes aren't for everybody.
I am only sharing things of interest to me and or things that might be of interest to others. The only way for us to know what's interesting to you..............is for YOU to start a thread or make comments to tell us.
This is the only way for MarketForum to blossom. My dream would be to see the non metmike posts outnumber the metmike posts by 50 to 1.
John, I've often thought of trying to learn another language, with Spanish being the logical choice ... but at my age, why bother ?
If I had any expectation of sticking around for quite some time, my choice would unfortunately be Chinese.
Mike, If I bet someone on the outcome of dropping a pound sack of flour and a pound of gold from a height of 100 feet, which would hit the ground first? I'm betting on the flour.
n
They will both have the same amount of attraction to the earth from gravity but I'm betting that the one that is more dense will fall slightly faster because it will be smaller and have slightly less wind resistance.
19.32 grams per cubic centimeter=density of gold
0.593 gram per cubic centimeter=density of flour
Since gold is 32.6 times more dense than flour, a pound of it will be 32 times smaller than a pound of flour(which will also be in a bag that adds a bit to the wind resistance). So the gold will hit first because it will have less wind resistance.
Why do you think the flour will hit first?
Why do you think the flour will hit first?
mike, because a pound of gold has 12 troy ounces (373.24 grams), while a pound of flour has 16 ounces (453.59 grams).
Why do you think the flour will hit first?
mike, because a pound of gold has 12 troy ounces (373.24 grams), while a pound of flour has 16 ounces (453.59 grams)
So it was a trick question eh carl?
Well, I have a non trick explanation for why the pound of gold will STILL hit first, even if the total weight is less for the gold. The reason is the same one that I provided earlier..............less wind resistance b
Because the gold is more dense and the size is much smaller. Granted, wind resistance is going to be fairly small over just 100 feet but being 32 times smaller is going to result in much less wind resistance a measurable difference.............gold hitting before the flour.
It's actually a common misconception that heavier objects will fall faster than lighter ones, all things being equal except for the weight.
https://www.wired.com/2013/10/do-heavier-objects-really-fall-faster/
Let's look at the case of a falling bowling ball and basket ball. This is a force diagram showing the two objects.
The bowling ball has a greater mass so it also has a greater gravitational force.
"Heavier things have a greater gravitational force AND heavier things have a lower acceleration. It turns out that these two effects exactly cancel to make falling objects have the same acceleration regardless of mass."
Air Resistance ————–
"Clearly, I didn't fully address all the issues above. If all objects have the same falling acceleration, then why did the crumpled up paper hit the ground before the foam board? The problem is that I left off a force - the air resistance force."
..... dude ..... the cole of slaw ......
5-1/2 foot drift
for "jumpers"
........... !!! ........... pppffttt !
..............jump....
1 . Suppose that two objects attract each other with a force of 16 units (like 16 N or 16 lb). If the distance between the two objects is doubled, what is the new force of attraction between the two objects?
Answer: If the distance is increased by a factor of 2, then distance squared will increase by a factor of 4. Thus, the inverse square law implies that the force will be "1/4" of the original 16 units. Therefore, the force of gravity becomes 4 units.
2. If you wanted to make a profit in buying gold by weight at one altitude and selling it at another altitude for the same price per weight, should you buy or sell at the higher altitude location?
Answer: To profit, buy at a high altitude and sell at a low altitude.
3. What would happen to your weight if the mass of the Earth somehow increased by 10%?
Answer: Your weight is nothing but force of gravity between the earth and you (as an object with a mass m). As shown in the above graph, changing one of the masses results in change in force of gravity. In this case, if the earth' mass goes up by 10%, then the force of gravity on you, or your weight, will increase by the same amount, that is 10%.
4. The planet Jupiter is more than 300 times as massive as Earth, so it might seem that a body on the surface of Jupiter would weigh 300 times as much as on Earth. But it so happens a body would scarcely weigh three times as much on the surface of Jupiter as it would on the surface of the Earth. Explain why this is so.
Answer: The effect of greater mass of Jupiter is partly off set by its larger radius which is about 10 times the radius of the earth. This means the object is times farther from the center of the Jupiter compared to the earth. Inverse of the distance brings a factor of 100 to the denominator and as a result, the force increases by a factor of 300 due to the mass, but decreases by a factor of 100 due to the distance squared. The net effect is that the force increases 3 times.
...propietary...
4X4 = 16
