Someone please help me with these symbols?

c0nfused34235

1. The problem statement, all variables and given/known data

I'm doing an impact physics for engineering question and I cannot tell the difference between

(v_A)_2x & (v_(Ax))_2.

* I don't think I'll need help with solving the actual question if I understand these variables.

2. Relevant equations

N/A

3. The attempt at a solution

I know that v_A is object A's initial velocity, however, I don't know how to deal with the _2x. As for the second term above, I have no idea.....

berkeman

Welcome to the PF.

Can you post a picture or scan of the use of those symbols?

tiny-tim

hi c0nfused34235! welcome to pf!

(try using the X₂ button just above the Reply box )

you mean (v_A)_2x & (v_Ax)₂ ?

what is the context?

c0nfused34235

Hi guys, thanks for the warm welcome and quick replies. Here's the question and it's solution. I was trying to figure it out (how they solve it) and I could not understand how they found the 2 variables in the red box (see image attached below). Thanks again.

Attached Thumbnails

 

NascentOxygen

(v_A)₂ is the final velocity of body A, i.e., its velocity after the collision

(v_A)_2x is the x-component of body A's final velocity after collision

(v_(Ax))_2 is the after collision value of A's x-component of velocity

The sum of the x-components of momentum of the system before and after the bodies collide remains constant. The same goes for the y-components of momentum.

tiny-tim

hi c0nfused34235!
(v_A)_2x and (v_Ax)₂ are the same

(i've no idea why they've done that )

so they just add (v_A)_2x + (v_B)_2x to (v_A)_2x - (v_B)_2x to get 2(v_A)_2x

(and subtract to get 2(v_B)_2x)

c0nfused34235

Could someone please solve for one of them (with steps)? I still don't understand how they solve for those variables. If they are indeed identical, why can't I substitute one set into the other formula? I get completely incorrect values.

c0nfused34235

YES I GOT IT!!!

Thanks for your help guys!