Physics question

[ray1970]

Need some science help.

If two identical objects are launched at an identical velocity but one object weighs five pounds and the other object weighs three pounds, which one will travel the farthest before coming to a stop?

For example, if both the three pound and five pound object are both pushed to say 40 mph and you don't figure in anything like gravity or whatever, which one will travel the farthest distance before coming to a stop?

Hope that makes sense. If not, I can try to clarify.

Thanks.

[Great-Kazoo]

Which has more drop @ 25 or 50 yards. The 9mm or 45?

[ray1970]

Which has more drop @ 25 or 50 yards. The 9mm or 45?

Lol. That really isn't where this is going.

Let's assume the objects aren't flying through the air. Let's pretend they are bowling balls and they are rolling. If a ten pound ball was released at twenty miles per hour and a fifteen pound ball was released at twenty miles per hour which one would go farther before coming to a stop?

[mb504]

you don't figure in anything like gravity or whatever

If you are excluding gravity, air resistance, rolling friction, and etc, why would either one ever stop?

[MrPrena]

Need some science help.

If two identical objects are launched at an identical velocity but one object weighs five pounds and the other object weighs three pounds, which one will travel the farthest before coming to a stop?

For example, if both the three pound and five pound object are both pushed to say 40 mph and you don't figure in anything like gravity or whatever, which one will travel the farthest distance before coming to a stop?

Hope that makes sense. If not, I can try to clarify.

Thanks.

Assuming it is vacuum and surface area is insignificant (going back to General phys), x is independent to y.
both are falling at "g" (9.8m/s^2) at y axis in Cartesian coordinate regardless of it being 5lbs or 3 lbs. Meanwhile, both are traveling at 40mph at x-axis.
Key word here is same velocity traveling in x axis.
If you get into momentum or energy, it will have different story.

Last year, I use to tutor undergrad physics, chemistry, economics, finance, and some math.
For you, i will tutor you for a glock. [LOL] (kidding)

[SamuraiCO]

If gravity, friction etc not affecting either ball there is nothing to stop either one. They both continue to travel until something stops their momentum.

Is that correct MrPrena?


Sent from my iPhone using Tapatalk

[MrPrena]

If gravity, friction etc not affecting either ball there is nothing to stop either one. They both continue to travel until something stops their momentum.

Is that correct MrPrena?


Sent from my iPhone using Tapatalk

Only thing it eventually stopping those 2 masses are gravity (g=9.8m/s^2) when it hit the ground some day.

Now, if those 2 items were thrown in the space without any gravity affecting it, it need reaction of same force to stop them.

[OldFogey]

Assuming both have equal energy inputs, the heavier ball would have to stop first. More energy required to move more mass. Assuming this is not in zero g space environment.

[JohnnyEgo]

Lol. That really isn't where this is going.

Let's assume the objects aren't flying through the air. Let's pretend they are bowling balls and they are rolling. If a ten pound ball was released at twenty miles per hour and a fifteen pound ball was released at twenty miles per hour which one would go farther before coming to a stop?

Taking your problem as presented, and with your assumption that no other forces (friction, air resistance, etc...) are applied, then the balls would be subject to Newton's first law of motion, also known as the law of inertia. Both objects would maintain their initial velocities (20mph) and neither would ever stop or slow down, as no other forces are acting upon them. This is what Mr. Prena said.

If we slowly step back from the idealized world, the first factor to come into play is force. It takes more force to get the 20 pound bowling ball up to the same velocity (20 mph) then the 15 pound ball. It will therefore take more force to stop the 20 pound ball. This represents the concepts of conservation of energy and momentum. One of the first forces to act against the balls will be rolling resistance with the surface. Assuming the coefficient of friction between both balls and the hard surface is the same, then it will take more exposure to the force of friction over time to make the heavier ball come to a stop. Thus, the heavier ball will roll further.

If you start adding in other factors, such as air friction, or movement up inclined planes, or surface elasticity, you start changing the sum of forces acting on the balls, and you can contrive a situation where either ball rolls farther.

[SuperiorDG]

If you are excluding gravity, air resistance, rolling friction, and etc, why would either one ever stop?

This ^^^

[00tec]

Taking your problem as presented, and with your assumption that no other forces (friction, air resistance, etc...) are applied, then the balls would be subject to Newton's first law of motion, also known as the law of inertia. Both objects would maintain their initial velocities (20mph) and neither would ever stop or slow down, as no other forces are acting upon them. This is what Mr. Prena said.

If we slowly step back from the idealized world, the first factor to come into play is force. It takes more force to get the 20 pound bowling ball up to the same velocity (20 mph) then the 15 pound ball. It will therefore take more force to stop the 20 pound ball. This represents the concepts of conservation of energy and momentum. One of the first forces to act against the balls will be rolling resistance with the surface. Assuming the coefficient of friction between both balls and the hard surface is the same, then it will take more exposure to the force of friction over time to make the heavier ball come to a stop. Thus, the heavier ball will roll further.

If you start adding in other factors, such as air friction, or movement up inclined planes, or surface elasticity, you start changing the sum of forces acting on the balls, and you can contrive a situation where either ball rolls farther.

Agree.

If you have 2 identical vehicles, with one containing extra weight (but had the exact same rolling resistance), and you were traveling 60mph, then let off the gas, the momentum of the heavier vehicle carries it further.

[Erni]

Only thing it eventually stopping those 2 masses are gravity (g=9.8m/s^2) when it hit the ground some day.

Now, if those 2 items were thrown in the space without any gravity affecting it, it need reaction of same force to stop them.
Yes, but if they were thrown in space around earth they would need a lot more velocity thsn 40mph to not fall back down.

[davsel]

https://thepractitionerd.files.wordpress.com/2013/11/wpid-screenshot_2013-11-15-14-35-19-e1385864668694.png

[JohnnyEgo]

I should clarify that the weight component of friction will mean that the heavier ball experiences more rolling resistance, but the magnitude of this difference will most likely be relatively minor in comparison to the momentum disparity between the two balls. One could do the math on this, but I can't before I have to get my kid to camp.

[ray1970]

JohnnyEgo and 00tec, I think you guys got what I was going after.

The vehicle analogy was a good one. Basically if both objects were traveling at the same speed and all of the forces acting on those objects was the same (wind resistance, rolling resistance, aerodynamics or each object, etc. and the force moving the two objects was removed I was thinking the heavier object would travel farther before coming to a stop.

Thank you all for information.

[MrPrena]

Yes, but if they were thrown in space around earth they would need a lot more velocity thsn 40mph to not fall back down.

Without gravity.
However you are absolutely right. I would not know any empty space which has pure zero gravity within x parsec.

Spacestation has about 94-95% earth'a gravity by doing univ gravity equn.
Even Neptune is effected by suns gravity.
Heck. Even the galaxy is spinning around the center.

[TFOGGER]

African or European swallow?

[Erni]

Ni.

[mb504]

I should clarify that the weight component of friction will mean that the heavier ball experiences more rolling resistance, but the magnitude of this difference will most likely be relatively minor in comparison to the momentum disparity between the two balls. One could do the math on this, but I can't before I have to get my kid to camp.

But he didn't want to use gravity in the original problem, rolling resistance requires gravity to hold the two surfaces together.

[kidicarus13]

You guys obviously have more free time than me.

[JohnnyEgo]

But he didn't want to use gravity in the original problem, rolling resistance requires gravity to hold the two surfaces together.

Guess you missed the first part of my prior post. If no external forces are applied to the balls, they continue to roll along at 20mph in perpetuity.
But Ray was really asking about the impact of weight (mass, really) on momentum for two otherwise equal objects. He just didn't use those words. The second part of my prior post answered that question.
The follow-up comment was for those who would argue about oversimplification of the model. It wasn't meant as a stand-alone post.

More to the point of what Ray was getting at, if you have two identical Kia Sephias travelling at 20 miles per hour, with one filled with feathers and the other with a equal volume of lead, and both drivers hit the brakes at the same time, the heavier one is going to take more energy to stop (rolls longer).

[00tec]

Guess you missed the first part of my prior post. If no external forces are applied to the balls, they continue to roll along at 20mph in perpetuity.
But Ray was really asking about the impact of weight (mass, really) on momentum for two otherwise equal objects. He just didn't use those words. The second part of my prior post answered that question.
The follow-up comment was for those who would argue about oversimplification of the model. It wasn't meant as a stand-alone post.

More to the point of what Ray was getting at, if you have two identical Kia Sephias travelling at 20 miles per hour, with one filled with feathers and the other with a equal volume of lead, and both drivers hit the brakes at the same time, the heavier one is going to take more energy to stop (rolls longer).

Which leads us to the next question: Which is heavier, an ounce of gold, or an ounce of feathers?

[davsel]

American or European ounce?

[spqrzilla]

Paging Galileo, paging Galileo. Mr. Galileo to the white courtesy phone....

[00tec]

American or European ounce?

I ain't European... haha

I'll add one:
Which is heavier, a pound of gold, or a pound of feathers?


It is a different answer....

[ray1970]

Lol. I was expecting maybe one or two replies. I had no idea this would lead to such entertainment.

Yes, I wasn't very good at explaining what I was trying to ask. Fortunately, JohnnyEgo has some experience dealing with kids so he figured out exactly what I was trying to ask.

[OtterbatHellcat]

African or European swallow?

Laden or unladen?

[Duman]

African swallow....

[cstone]

https://www.youtube.com/watch?v=zDcf7eEaP0M


https://www.youtube.com/watch?v=PWNs7i4rEWA

[Duman]

Two Kia Sephia's crashing? Can't think of a better ending for a Kia....