Is mass the same thing as velocity?

Question

Is mass the same thing as velocity? If not, what are the differences? I'm a physics grad student, so don't be affraid to use technical terms.

Answer 1

Physics graduate student, eh? Then this is a quiz question and I'm happy to demonstrate the huge gaps in my understanding of theoretical physics. I expect that you'll want to clarify and correct me. I invite no less!

Because we know that the speed of light is a constant with respect to all inertial reference frames (this is an experimentally demonstrated phenomenon), it follows that time is actually a non-independent variable and is relative to the inertial reference frame. This is why post-Einsteinian language includes the concept of "spacetime", a non-Euclidean geometry of time and space quantities.

My understanding is that the geometric phenomenon of spacetime with fixed lightspeed irrespective of reference frame forces the "F=ma" expression into yielding some interesting correlates. For example, the relative "time-dilation" that results from acceleration creates an absolute mathematic maximum velocity at lightspeed. Because the "a" (acceleration) is a measure of velocity with respect to time, and time is now dependent on velocity with respect to the speed of light, the response to the same "F" applied at different velocities becomes different. This shows that mass "m" is actually a variable dependent on "a".

My understanding is that this is the kernal of the thought experiment that led Einstein to derrive the result "E=mc^2" which follows on the use of the kinetic energy equation, "KE=1/2mv^2".

This redefines mass as a measure of the inherent energy of matter. Mass is the same thing as energy. Energy (and therefore mass) increases by accelerating.

It's been quite a while since I read about this or about the mathematics that underly these conclusions. However, I've re-read my answer twice and it expresses what I remember fairly well.

I hope that helps!

How'd I do?

Answer 2

How are you physics grad student? Mass is roughly the measure of "how much matter there is in an object." People often confuse this with the concept of weight. Velocity, on the other hand, is defined to be the rate of change of position. In layman's terms, it is the same thing as speed but also includes direction. So... mass and velocity are in no way the same; they are completely different! Where exactly can you be a grad student in physics and not know this?

Answer 3

Acceleration is the rate of change of velocity. If you drop a stone over a cliff, gravity will exert a constant force on the stone, which causes it to accelerate (F=ma) with CONSTANT acceleration a (10m/s/s). So the acceleration is the same (ignore air Resistance) and the stone gets faster and faster. So the velocity is changing but the acceleration is not. That's the difference between them. The formula that links acceleration and force is F=ma, where m is the mass. Push something with constant force in outer space, and it will get faster and faster. If you want something to link velocity and force, try Ft=mv-mu. In other words, push something with force F for time t and the difference in momentum is mv-mu. If you know the mass of the thing you pushed, then the change in velocity is (force X time)/mass = difference in velocity. Hope this helps

Answer 4

No. And don't tell me a Physics grad student doesn't know the difference between mass and velocity.

F= m A, force = mass times accelleration
where accelleration = dV/dt where V = velocity. Clearly they are not the same.

Answer 5

I am afraid to go technical.

Mass is the amount of substance in a body. Velocity is the rate of displacement in a certain direction.

Now by any chance did you mean the difference between Speed and Velocity?

Answer 6

Mass is the quantity of matter. Velocity is the speed & direction of its movement. A car may have a mass of 1500 kg & a velocity of 100 kph at 180º (due south.

Answer 7

NO!

Mass is something that exists and sometimes moves, however Velocity is always at motion. Something in motion is always at a constant velocity and unless something of equal or greater force acts upon it, then it will still remain at the same constant velocity.

Answer 8

Shame! Shame! Shame!
Pride plus arrogance equals an untenable superiority complex. You need to see a mental health specialist.

Answer 9

you said what? your not very far along in your studies are you? i think i found your mistake or not. maybe you mean weight that is similar to how the gravity afects an object but i dont know you might like to rethink your question!

Answer 10

grad student huh? did your parents buy your way through college?