That's exactly correct. Consider the equation for kinetic energy: E = 1/2 m*v^2 The energy to go from 0-10 m/s is the difference in this value (for 1kg e.

That's exactly correct. Consider the equation for kinetic energy: E = 1/2 m*v^2 The energy to go from 0-10 m/s is the difference in this value (for 1kg e.g.): dE = E1 - E0 = 1/2(10^2) - 1/2(0^2) = 50J To go from 10m/s to 20m/s: dE = E2 - E1 = 1/2(20^2) - 1/2(10^2) = 200 - 50 = 150J In fact by solving for velocity you can figure out what happens if you put another 50J into your object that's already going 10m/s: v = sqrt(2*E) = sqrt(200) = 14.1m/s When you double the energy, you only get 1.4 times the speed.