spetznaz
Senior Fanboy Killer
Originally posted by aliveinboston
Where do you get F is inverse to MxA from what I wrote?P=FxV
If P is fixed (ie., Superman cant suddenly become more powerful than he was before) then if V increases (the speed at which he moves), his F decreases (the Force he can apply). Get it?
Lets toss in some numbers to illustrate the point.
P=100
F=X
V1=2
V2=10
If Superman's power is 100, and his velocity (V1) is 2, his force (F) = P/V1 = 100/2 = 50
If he moves faster and his velocity (V2) is 10, then his force (F) = P/V2 = 100/10 = 10
Get it?
Force is inverse to Velocity where Power is a constant. In other words, the faster he moves the less force he can apply.
If you understand electric motors then you would be able to understand that for a certain amount of power (kilowatts) when you increase the rpm your torque decreases and at lower rpm you will have more torque.
LOL.
Ok, here goes:
1) You said the following: '
Power is a combination of force and speed. Assuming that we are talking about a fixed amount of power, then more speed = less force.'
In essence you are saying that the faster Superman goes the less force he will have.
That is baloney (politely speaking), and against F=MxA.
The faster Superman goes, meaning the faster he accelerates towards the greater speed, the more force he will apply.
That goes against what you were saying (and unless you are willing to rewrite some of the most basic bastions of Physics just admit you are wrong).
2) Now, in the post above you put the following formula:
P=FxV.
Power is basically energy (or work) transferred per unit time,and the formula you put basically states it in the form of the object's force multiplied by the object's velocity.
Thus it is an accurate formula.
However just because you can jot down a formula accurately doesn't mean squat if you do not comprehend its application (and the way you explained the whole thing,including your nice lil' numbers, shows rudementary comprehension at best).
P=FV
Correct.
However that can be expanded into the following:
P=FV
= (funct. of) F x s. where F is force, and s. is displacement
= (funct. of) (MA).s where F is broken down to Mass x Accel.
Now, guess what happens when Superman starts to move faster (in other words, when his rate of speed increases ....otherwise known as acceleration)?
His A goes up, and thus F (being equal to M.A) goes up as well.
Consequently F is higher, and with P being equal to F.V the power he can do goes up.
Thus there is no rationale for you to say that power remains constant. That is an irrational (and incorrect) assumption.
Let's go to the real world.
The US is working on an anti-ballistic missile program, whereby a kill vehicle is mounted on a missile.
The kill vehicle has absolutely no explosives .....the way in which it destroys the incoming ICBMs (as opposed to the 1960s Sprint and Spartan programs that entailed nuclear warheads), is by using kinetic energy to smash into the ICBM and vaporize it.
To do this it accelerates to tremendous speed (hypersonic), and even though it is a relatively small KV it still produces enough force to literally turn the oncoming missile to dust.
Now, according to your post, the faster the KV went then the less force it would have!
You said the following: ...if V increases (the speed at which he moves), his F decreases (the Force he can apply). Get it? .....
Hmmm, you ARE saying that the faster an object moves (the faster its rate of speed increase, i.e acceleration, is) that the less F becomes.
An increase of V means that acceleration is taking place; i.e it goes from V1 to V2 over a period of time. And you are saying that when that happens Force decreases!
I'm sorry, but that is inane.
(BTW ...if you can coherently prove otherwise you just nabbed yourself a Nobel prize in physics).
