Who can answer this technical conundrum and apparent paradox re ft/lb energy?

[Geezer]

https://en.m.wikipedia.org/wiki/Kinetic_energy

Or try this.

I have no idea why this is the case (non-linear relationships between increases in mass versus increases in velocity) but physics says that similar increases in velocity at the same weight increase energy far more than similar increases in mass while velocity stays constant.

Momentum, on the other hand, is linear.

https://en.m.wikipedia.org/wiki/Momentum

I hate physics. It’s annoying. Unfortunately, it appears to be real and true. Bloody science.

[bill57]

I hate physics. It’s annoying. Unfortunately, it appears to be real and true. Bloody science.

When I was at school, the standard text was "Physics is Fun" by Jim Jardine. Apparently it was not uncommon to open one, and pencilled inside would be "Jardine's a bloody liar".

[Geezer]

When I was at school, the standard text was "Physics is Fun" by Jim Jardine. Apparently it was not uncommon to open one, and pencilled inside would be "Jardine's a bloody liar".

The only time I can recall physics being fun was building a ballistic pendulum to test the muzzle energy of an ASI/Gamo Expo/Sniper (the school’s not mine) and then me explaining why it’s results were wrong. And, though not physics, being told that I could definitely not build a Sten gun as my metalwork project.

[deejayuu]

In layman's terms. Try riding a bicycle on the flat in still air. Unless you're an accomplished cyclist getting above 15 mph, sitting upright, becomes very hard work. Non linear drag

[andrewM]

How very kind of you scientific fellows to try to re-educate me and to take the time to explain the physics, here (this forum has some considerable expertise).

I understand the formula and the calculation. Trying to rationalise it in my mind is rather less easy but, happily, I think I am not the only one, here! I am also better informed that when I began.

Rgds to all.
A

[ccdjg]

At the risk of boring the pants off everyone, I can add a bit more to the explanation. It is a misconception to think of the kinetic energy of a moving object as coming directly from its velocity, as it actually comes directly from the acceleration needed bring the object up to that velocity in the first place.

Imagine the pellet sitting in the barrel at rest, with zero velocity and zero energy. When the force from the compressed hits it, it is then rapidly accelerated along the barrel under the effect of the constantly applied force, the velocity increasing progressively until it leaves the muzzle. The law of physics states that the energy transferred to an object in such a process is given by the mass of the object, m, multiplied by the acceleration, a, and the distanced moved d.
Easy to remember as: E = m.a.d.

Acceleration is not the same as velocity, but is the rate at which the velocity is increasing. Acceleration times distance, a.d., is related to velocity squared, not velocity, which is why the kinetic energy of the pellet is not simply proportional to the velocity of the pellet.