# Homework Help: Physics; two forces on an object

1. Sep 22, 2009

### triplel777

1. The problem statement, all variables and given/known data

Two forces FA and FB are applied to an object whose mass is 16.0 kg. The larger force is FA. When both forces point due east, the object's acceleration has a magnitude of 0.900 m/s2. However, when FA points due east and FB points due west, the acceleration is 0.400 m/s2, due east. Find the magnitude of FA and the magnitude of FB.

2. Relevant equations

3. The attempt at a solution

well Fnet= Fa+Fb= ma
so Fnet = 16*0.9
Fnet= 14.4
now what do i do?

2. Sep 22, 2009

### rock.freak667

When both are in the same direction

Fa+Fb=ma (a = 0.9)

when in opposite directions Fa-Fb=ma, this a is in the second line of the problem

3. Sep 22, 2009

### triplel777

yes so Fa+Fb=14.4 how do i find the value of each one?

4. Sep 22, 2009

### rock.freak667

you have

Fa+Fb= constant

and

Fa-Fb= other constant

two equations with two unknowns, solve simultaneously.