Question

A massless, rigid board is placed across two bathroom scales that are separated by a distance of 1.89 m. A person lies on the board. The scale under his head reads 470 N, and the scale under his feet reads 334 N. (a) Find the weight of the person. (b) Locate the center of gravity of the person relative to the scale beneath his head.

Answer 1

A. 119kg

B.0.53m from head

Step-by-step explanation:

A. Weight = 730+340.

=1170N

F= Wg

W = 1170/9.8

= 119kg

If x is distance from head to CG then 1.92–x is the other distance.

Moments must equal

470x = 330(1.89–x)

470x = 623.7 – 330x

1170x = 623.7

x = 0.53m from head