Recent content by penutbutr

Did this method now, and got the answer 18 joule which verifies it :thumbup:

Oh, That makes sense! So kinetic energy is always relative to something, the more speed an object has the more destruction it can cause at the object in rest. Meanwhile an object traveling close to the speed of the other object will perceive it as having less kinetic energy.

How can it be harder to accelerate an extra 1 m/s, in high speed like 50 m/s ? than it would be in low speed like 2 m/s. That is what the latter method implies, right?

So in order to get correct calculations. "v" in the formula mv2/2 can only be measured by someone in rest relative to the mass?

Homework Statement Calculate the energy needed for 1 kg mass at the velocity of 2 m/s go up to the velocity of 6 m/s. Homework Equations Ek = mv2/2 The Attempt at a Solution From the mass point of view, it is stationary and goes up to a velocity of delta (6-2) m/s = 4 m/s so the energy needed...