# Homework Help: Can both these questions give the same answer

1. Feb 23, 2016

### lioric

1. The problem statement, all variables and given/known data
I posted this question on the quantum forum but it got deleted saying that I was cheating on homework

I only need a simple yes or no

This is the original question

This is the question my teacher gave

As you can see in the total energy formula is missing an extra square. The original question has c^4 but the one that my teacher gave has c^2

Can both of these give the same final answer which is supposed to be u

2. Relevant equations
All the equations are given in the question

Y= square root 1/1-(v/c)

3. The attempt at a solution

I don't need anyone to tell me how to do the question
I have done both versions and the text book question resolves to final answer as u

But the one my teacher gave doesn't end up. I did both side by side and I find the extra c^2 which is missing plays a huge role in resolving the final answer

I just need a yes or no. Please

2. Feb 23, 2016

### TSny

If a formula has two terms that are added and the dimensions (or units) for the two terms are not the same, then the formula cannot be correct.

3. Feb 23, 2016

### lioric

Thank you very very much
I have been doing this question all night and only now realised that they were different I had previously done this question from the text
But last night I just couldn't get the ends meet
Finally I did both side by side and found the typo
But I was just thinking it may still work out
But even then the ex didn't get the correct answer
So I just wanted to check
Thank you
I can finally sleep :)