# How to calculate the ratio of weight?

1. Feb 6, 2012

### asteorit

1. The problem statement, all variables and given/known data
Two body move apart by force. Frictional forces are considering. How to calculate the ratio of weight?
m1<m2
Ft1=k*g*m1
Ft2=k*g*m2

2. Relevant equations
v1(t1)=$\frac{F_{t1}-F}{m_{1}}$*t$_{1}$
x1(t1)=$\frac{F_{t1}-F}{m_{1}}$*$\frac{t^{2}_{1}}{2}$

v2(t1)=$\frac{F-F_{t2}}{m_{2}}$*t$_{1}$
x2(t1)=$\frac{F-F_{t2}}{m_{2}}$*$\frac{t^{2}_{1}}{2}$

What is the procedure of calculation.
Thank you for your help.

File size:
15.2 KB
Views:
163
2. Feb 6, 2012

### tiny-tim

welcome to pf!

hi asteorit! welcome to pf!

sorry, but i don't understand the set-up

what is the connection between these two bodies?

3. Feb 7, 2012

### asteorit

Re: welcome to pf!

Hi tiny-tim,

These two bodies are connected by linear actuators. Force F of the linear actuator, will act on both the bodies. We know that the bodies should move along the path L, L=x1(t1)+x2(t1). We know that m1<m2.
If I assume correctly, and the trajectory of bodies depends on the mass ratio. Or is also dependent on the time t1?
What is the ratio of the mass of bodies$\frac{m_{2}}{m_{1}}$=?, if the sum of their orbits must be equal to L?

4. Feb 7, 2012

### tiny-tim

hi asteorit!

i see … so it's equal-and-opposite-reaction-forces, but without contact

ok, then start by writing out Ftotal = ma for each body …

what do you get?

5. Feb 7, 2012

### asteorit

I do not understand it, to me you ask? Some will not understand it?
Because I need to know what is the ratio of the masses.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook