Showing px-Et is invariant using Lorentz Transformations

[Nitric]

1. Using the Lorentz Transformations, show that the quantity px - Et is invariant, where p and E are the momentum and energy, respectively, of an object at position x at time t.
2. px - Et
3. I needed help on starting the problem. Where should I begin?

 

[tiny-tim]

Using the Lorentz Transformations, show that the quantity px - Et is invariant, where p and E are the momentum and energy, respectively, of an object at position x at time t.

Hi Nitric!

Hint: what 4-vectors can you see in this problem?

 

[Nitric]

Hi Nitric!

Hint: what 4-vectors can you see in this problem?

p x E and t?

 

[tiny-tim]

p x E and t?

erm … nooo

 

[Nitric]

Damn. Well I honestly have no idea, kinda stuck on this problem