Center of mass: 2 objects in triangle system

[IDKPhysics101]

Three objects of different masses are located at the corners of the triangle shown in the picture. If distance a equals 4.21 m, b equals 1.55 m, and c equals 11.93 m, then what is the center of the mass (in m) of the system in the horizontal with respect to the origin?

X center of mass=6.2/6m+4.21(if set beginning of b as reference point zero then add it in the end to find respect to the origin)=5.24?


I don't have time to type my work right now. But will show work if answer is wrong to see where i went wrong.

 

[tiny-tim]

Three objects of different masses are located at the corners of the triangle shown in the picture. If distance a equals 4.21 m, b equals 1.55 m, and c equals 11.93 m, then what is the center of the mass (in m) of the system in the horizontal with respect to the origin?

X center of mass=6.2/6m + …

no, not 6.2, try again

 

[IDKPhysics101]

well my total answer was 5.24, is that correct?

 

[betel]

No, neither is 5.24

 

[IDKPhysics101]

xcm= (2m*4.21) + (3m*5.76) +(m*7.31)
---------------------------------
2m + 3m + m

xcm=5.5?

 

[tiny-tim]

xcm= (2m*4.21) + (3m*5.76) +(m*7.31)
---------------------------------
2m + 3m + m

xcm=5.5?

Yes, 5.5 is correct, but you really do need to go back to your original method (which was better) to see why the 6.2 was wrong

 

[IDKPhysics101]

yeah, i realized that i was making 4.21 the origin or the point of reference or something to get the center of mass for just the system no regarding the origin and just adding it in at the end

 

[betel]

Well that's correct basically and the easier way. We just don't know how you got your 6.2 in the first post.

 

[IDKPhysics101]

Xcm=(2m*0)+(3m*1.55)+(m*1.55)
-----------------------------
(2m+3m+m)

 

[betel]

Are the 3m and the m mass at the same value of x? At least that is what you wrote there. Look at the sketch again.