How much energy is produced when you push a box with a mass of 10kg at the speed of light?

Answer 1

A moving box doesn't produce energy. If you want to move the box, then YOU

have to produce whatever energy it requires. Normally, you take energy out of

food, and run it through your muscles to move things.

That's only one of the myths, misunderstandings, and unscientific contortions

packed into your brief question. I'll try to deal with a few more:

-- It doesn't take any energy at all to move an object at a constant speed. Once

you push it up to the speed you want, you can let go, and it keeps going at the

same speed in a straight line forever ... as long as nothing comes along to slow it

down or stop it, like friction, air, or a brick wall.

-- The mass of the box depends on its speed. At what speed is its mass 10 kg ?

-- Anything that has any mass when it's sitting still, or when it's moving at

any speed less than the speed of light, would have infinite mass at light speed.

So as far as that object is concerned, light speed is never going to happen.

-- If you want to make an object move faster, you have to come up with more

energy somehow, then push the object in order to pump that energy into it.

Since the object's mass is growing as it moves faster, the amount of energy

you have to supply to make it go even faster keeps growing too. If it ever gets

anywhere near the speed of light, then its mass is heading toward infinity, and

so is the amount of energy you need to add to it for any increase in its speed.

Sooner or later, the amount of energy you'll need to make it go 1 mph faster will

be more than the electrical energy that everyone in the USA uses in 10 years.

-- Also don't forget ... all the while you're doing this, YOU have to keep up with

the box so you can stretch out your arms and keep pushing it. So YOU have to

keep moving faster and faster, and YOUR mass keeps growing too, and you need

more and more energy just to stay even with the box so that you can push it.