Do the brakes have to do more work (ignoring air resistance) slowing a vehicle from 10m/s to 8m/s than from 8m/s to 6m/s? Say a 1000kg vehicle is moving at 10m/s, it has kinetic energy of 0.5 x 1000 x 10 x 10 = 50,000 J Then the brakes are applied, and it slows to 8m/s, so now has kinetic ener...