# B Binding energy

1. Sep 11, 2016

### Tris Fray Potter

If the binding energy in nuclear physics is e=mc^2, then would the binding energy of a larger object be:
e=mv^2
where v=the velocity of the asteroid?

2. Sep 11, 2016

### Simon Bridge

In the binding energy equation the m is the mass deficit ... does the concept of mass deficit apply to the asteroid?
In the asteroid equation, v is the speed of the asteroid; in the binding energy, the speed "c" appears in the same place... does that mean that the nucleus is moving at the speed of light?
In short: no. You cannot do physics by analogy.

3. Sep 11, 2016

### Tris Fray Potter

Okay. Thank-you. Do you know how I would be able to find the binding energy of the asteroid?

4. Sep 11, 2016

### Drakkith

Staff Emeritus
There are several types of binding energy. Which one are you looking for? Gravitational? Nuclear? Chemical?

5. Sep 11, 2016

### Tris Fray Potter

I think gravitational. I need to know if a bomb would explode an asteroid or not, and I was going to do a comparison on the energy of the bomb (which I've already figured out), to the binding energy of the asteroid.

6. Sep 11, 2016

### Drakkith

Staff Emeritus
7. Sep 11, 2016

### Tris Fray Potter

8. Sep 11, 2016

### Staff: Mentor

Note that the binding energy of an asteroid also contributes to its mass via E=mc2 as every energy in the rest frame does, but the contribution is completely negligible.

9. Sep 11, 2016

### Simon Bridge

... if the idea is to destroy the asteroid before it arrives at some target, detonating it won't remove it's kinetic energy (though distributing the bits over a big volume can reduce the amount of mass that strikes the target. Phil Plait has an artical about it.