Question

4 Four objects are stiuated along the y axis as follow: a 20 kg object is at +3 m, a 3 kg object is at +2.5 m, a 2.5 kg object is at origin, and a 4 kg object is at -5 m. What is the center of mass of these objects?​

Answer 1

Answer: 1.348 meters

Explanation: Although the sign is missing from the location of the 4.00 kg object, it is assumed to be positive. The net moment of all the objects about the center of mass must be zero. Let the center of mass be on the y axis at a point  c . Adding the four moments together, we get:

(2.00)(3.00−c)+(3.00)(2.50−c)+(2.50)(0−c)+(4.00)(0.500−c)=0

6.00−2.00c+7.50−3.00c+0−2.50c+2.00−4.00c=0

11.5c=15.50

c=  1.348 metres

The center of mass is on the y axis at  y  = 1.348 metres.