1. ## A Practive Exam

Hello, I recently started Calculus and I was hoping you could help. I will be doing my best to work through them and posting my results here as examples of what (or what not to) do. I'm not a terrific student at this point, which is what prompted me to join this forum, so don't expect amazing work from me.

1. Three point-masses of 100, 80, and 70 kg are located at -3, 2, and 4, respectively, on an x-axis. Find the center of mass.

2. Hi Selim, welcome to our forum, please post only 1 question per thread with your attempts at working it out.

This will be best for everyone.

3. Originally Posted by Selim
Hello, I recently started Calculus and I was hoping you could help. I will be doing my best to work through them and posting my results here as examples of what (or what not to) do. I'm not a terrific student at this point, which is what prompted me to join this forum, so don't expect amazing work from me.
Multiply each mass point by its coodinate. Find the sum of these products.
Divide this sum by the sum of the masses. The answer is the coordinate of the center of mass.

4. (100*-3)+(80*2)+(70*4)=140
100+80+70=250
140/250=14/25

Is that correct?

5. Originally Posted by Selim
(100*-3)+(80*2)+(70*4)=140
100+80+70=250
140/250=14/25