Kinetic Energy Calculator

In short Kinetic energy is ½mv², so 2 kg moving at 3 m/s carries 9 joules. The square is the entire story and it is worth internalising: doubling the speed does not double the energy, it quadruples it. A car at 100 km/h carries four times the energy it has at 50, and every joule of that has to go somewhere in a crash — into crumpling metal, into brakes, into heat. It is also why stopping distance grows with the square of speed rather than in proportion, and why speed limits that look like small differences are not. The same formula connects speed and height. Setting ½mv² equal to mgh cancels the mass and gives h = v²/2g, so this page shows the height an object could reach if all its motion went into climbing — or equivalently, the drop that would produce its current speed. That is the same conservation the free-fall page uses, arrived at from the other side. Kinetic energy is a scalar, with no direction: two objects meeting head-on have zero total momentum and a great deal of energy, which is exactly why that crash is the violent one. One honest limit: this is the Newtonian formula, and it understates the true energy as speed approaches that of light — by about 0.75% at a tenth of light speed, and by far less than your inputs' precision at any ordinary speed.