Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Other Topics => Topic started by: shooter on September 28, 2024, 05:28:10 pm

Title: force math
Post by: shooter on September 28, 2024, 05:28:10 pm
I want to argue with folks in tin-foil country, but I want to be correct. Used a calculator to get F=
What I’m not sure with is the result, simply pounds force? Or Newtons force?
Weight           833000 lbs    377842Kg     
Speed            550mph         807Ft/sec       885Km/h        246m/s
           
F = 833000lb * 807ft/s = 672,231,000 lb?
F = 377842Kg * 246m/s = 92,949,132 N?
 
Going here next, need more data!
 
  Impulse is the product of a force and the time over which it is applied (I = ∫F dt). 
Title: Re: force math
Post by: separateness on October 01, 2024, 01:35:46 am
A nitpick: Acceleration is distance per time squared. ie m/s2 or ft/s2
1 newton does indeed equal 1 kg x m/s2.  I am not sure what the equivalent would be in freedom units.
I hope I managed to address at least one of your questions.
Title: Re: force math
Post by: acheld on October 01, 2024, 01:07:44 pm
Hmmm, the only guys I know using impulse (or specific impulse) are rocket men.  Arguing with them is always a challenge, though it is possible.   It's only physics!
Title: Re: force math
Post by: scstill on October 01, 2024, 03:56:32 pm
Besides rocket men, when I buy another guitar, I often use impulse
Title: Re: force math
Post by: shooter on October 01, 2024, 05:59:51 pm
 :laugh:


I had to do rocket science math, but it was >40years go, then I got a fluke, scope n never looked back!


so when a moving object hits a stationary object, it's not simply Newtons force?  or pounds force?  I need the delta dt in the answer?
Title: Re: force math
Post by: acheld on October 01, 2024, 09:03:31 pm
:laugh:
so when a moving object hits a stationary object, it's not simply Newtons force?  or pounds force?  I need the delta dt in the answer?

Oh, this question takes me back 50 years to when I was teaching Newtonian physics.  I was not an effective teacher, bear in mind.    :laugh:

The direct answer to your question is that units of force are Newtons, dynes, pound-force, and others.

Force is defined as what happens to an object that has "force" applied to it.   So, when a solid object is knocked by something, the force of the knock is defined by the mass of our object times the acceleration that results from the knock.  So, yup the force would be mass (kg) times the acceleration that occurs (m/s/s).   

Real world events, such as "what is the force of a 20mm bullet hitting an armored target" get very complicated very fast, though.  Objects deform, motion is converted to heat via friction, etc etc. 

When you use pounds in these calculations, you have to be mindful of the context.  Is the pound a mass, or is it a force (mass x gravitational acceleration).  Check out https://en.wikipedia.org/wiki/Pound_(force)#:~:text=In%20other%20contexts%2C%20the%20unit,unit%20of%20mass%20is%20lb.&text=In%20the%20%22engineering%22%20systems%20(,unit%20(pound%2Dforce). (https://en.wikipedia.org/wiki/Pound_(force)#:~:text=In%20other%20contexts%2C%20the%20unit,unit%20of%20mass%20is%20lb.&text=In%20the%20%22engineering%22%20systems%20(,unit%20(pound%2Dforce).) for definitions (it is not a pretty picture).   For example, when we talk about torque we commonly use pound-feet -- in that context the pound is a force, not a mass.




Title: Re: force math
Post by: shooter on October 02, 2024, 05:46:47 am
Quote
The direct answer to your question is that units of force are Newtons, dynes, pound-force, and others.


thanks, ya, just want simple for now, but winters coming so I may go down the "complex" road, later!


as a rock climber for 20 years, I felt all the "weight" of all that math as I came to abrupt stops!!!  :icon_biggrin: