World Science Scholars

### 41.3 Implications for Mass: Intuitive Explanation Discussion Back To Course
• Imagine a factory has created two identical blocks of wood. One of the blocks is stationary next to you, while the other has been set in motion and is speeding by you. What would you say about the density of the moving block compared to the stationary block?

Hint: The density of an object is its mass divided by its volume.

• Density of the block will increase as d = m/v
so as mass increases with increasing velocity and length is lorentz contracted
thus both factor will lead to increase in density

• Because length at rest is divided by gamma, the density at rest will be multiplied by gamma squared.

• Seems like the density will go up because of Lorentz contraction and mass increasement.

• As mass increases we know density increases

• The density of the block would increase by a factor of (gamma)^2 due to Lorentz contraction by a factor gamma and increase in mass by a factor of gamma

• I agree the density should increase. Interesting how quickly that would happen, as the mass is increasing and the volume would be decreasing because the length would contract as well.

• The block is Lorenz contracted (in the direction of the speed, 2 other measurements stay the same), so the volume decreases by a factor of gamma. The mass is increased by a factor of gamma. Which means that the density, whici is mass divided by volume, increases by a factor of gamma^2.

You must be logged in to reply to this discussion.

Send this to a friend