Inclined Plane w/ Two Masses: F=ma+mb?

AI Thread Summary
The discussion revolves around solving a physics problem involving two masses on a frictionless inclined plane connected by a pulley. The masses are mA = 2kg on the incline and mB = 3kg hanging vertically. Participants emphasize the importance of drawing free body diagrams for both masses to analyze the forces acting on them, including gravitational force and tension. The normal force is clarified as being perpendicular to the slope, and the tension in the cord is noted to be equal for both masses. The conversation highlights the need for correct equation formulation and understanding of the forces involved to solve for acceleration.
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Homework Statement


Block of mass mA = 2kg - lying on frictionless inclined plane with a slope of 20 degrees.

connected to mA via frictionless, massless pulley and massless cord... mB = 3kg

http://img152.imageshack.us/img152/8286/imag0103l.jpg

Homework Equations



F= Mass * Acceleration

Acceleration = Mass / Force

The Attempt at a Solution



so far all I can get is the free body diagrams..
would this follow a = Fga + Fgb / ma + mb?

except I don't have force..
 
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You have to draw 2 diagrams.
1. Forces exerted on mass#1
2. Forces exerted on mass#2

Make the unknown force as T.
 


I have drawn two diagrams? I attached a picture. So I'm just calculating the tension force?
 


ksm2288 said:

Homework Statement


Block of mass mA = 2kg - lying on frictionless inclined plane with a slope of 20 degrees.

connected to mA via frictionless, massless pulley and massless cord... mB = 3kg

http://img152.imageshack.us/img152/8286/imag0103l.jpg

The normal force N is perpendicular to the slope. It is not vertical.
What do you call Fgma and Fgmb?
You drew only one force exerted to mb. You need to draw the force of gravity, too.
Remember that the tension, the magnitude of the force the cord exerts, is the same on both bodies.

ksm2288 said:

Homework Equations



F= Mass * Acceleration

Acceleration = Mass / Force

The Attempt at a Solution



so far all I can get is the free body diagrams..
would this follow a = Fga + Fgb / ma + mb?

except I don't have force..

The equation is incorrect. You miss a few parentheses.
Explain, what Fga and Fgb are.


ehild
 
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