Blocks A and B are sitting side by side (touching) on a horizontal surface. A constant horizontal force Fa is applied to block A, which pushes against block B with a 32.0 N force directed horizontally to the right. The same force Fa is applied to block B; now block A pushes on block B with a 16.0 N force directed horizontally to the left. The blocks have a combined mass of 30.0 kg.
(a) What is the magnitude of the acceleration of the blocks in figure (a)?
(b) What is the magnitude of the force Fa?
Fnet = ma
The Attempt at a Solution
Part 1: Fa pushes on block A:
Block A has Fa pushing to the right, and block B pushing to the left so
Fnet = massblockA *acceleration = Fa - 32N
Block B pushes back on block A (only horizontal force on it)
Fnet = massblockB *acceleraton = 32N
mass blockA + massblockB = 30kg
Using these three equations I solved for Fa and got that Fa = 30kg*acceleration...
I thought that I could use the next set of data (Fa pushing on block B) to come up with another equation, then I could solve for Fa and acceleration, but the equations are exactly the same, so pretty useless.
Any help would be great, thanks!
(ps~ I sometimes have trouble with FBDs, so if something is wrong with how I laid out the forces, it would be great to know!)