Where is the Center of Gravity of a Lying Person?

[VanKwisH]

Homework Statement

A 160cm tall person lies on a light(massless) board which is supported by two scales , on under the feet and the beneath the top of the head. the scale under his feet read 29.4kg
and the scale under his head reads 32.8 kg ... where is the center of gravity of this person??

Homework Equations

The Attempt at a Solution

 

[foxjwill]

What have you tried so far? It's always a good idea to start with a picture and a force-body diagram.

 

[physixguru]

the simplest method to solve the problem is to calculate net torque abt the center of mass of person [take it as xi^+ yj^] from both the sides.then calculate the difference in the torques to get the value which gives the distance from the center of mass.

first proceed with the first step and update me of the progress.

 

[VanKwisH]

huh ? i don't understand

 

[VanKwisH]

what u mean is ... take the torques from each side ... and use the very middle of the person as the pivot point? am i correct ?
if so i got
t1 = 32.8 * 80
= 2624
t2=29.4 * 80
= 2352
does that look right??

 

[physixguru]

comeon..how can you take the distance as 80 cm??

take it as .80m

the new relations are;

t1=.80*32.8
=26.24

t2=29.4*80=23.52

 

[VanKwisH]

yah alright i get that ... next step??