Pushing a wall


by goosedennis
Tags: wall
goosedennis
goosedennis is offline
#1
Apr1-11, 04:35 PM
P: 1
If you were to push a wall and it were to not accelerate, would this mean you did not apply force to the wall according to the equation F=ma?
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artikk
artikk is offline
#2
Apr1-11, 05:15 PM
P: 19
The equation relates a NET force to the product of mass and acceleration. So even if you're pushing a wall, the applied force will probably will not be enough to move it since the wall is attached to the building and has its own weight. The force of the wall's weight and its connection with the building would be enough to counteract the force you applied on the wall. Now if you try to deform the wall, I think you would be just dealing with normal force and pressure( maybe surface tension?). I'm not an mech. engineer so I'm not familiar with the concepts.

To make the problem simpler, if the wall was separate from the building and on a plane with friction, then it's a simple free-body diagram problem. Assuming you're pushing from the left, then you would just have friction force acting in the opposite direction, to the right. If you overcome the friction by pushing with more force to the left than friction to the right, then you can easily accelerate the wall. I didn't include air resistance in the situation but I'm not sure about the equation for that.
The friction force would be
N=mass of wall*g
Ff=us*N, us =static friction coefficient, usually between 1 and 0.
Drakkith
Drakkith is offline
#3
Apr1-11, 07:33 PM
PF Gold
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P: 11,031
As artikk said, you are applying a force to the wall. The net force on the wall is zero however. You aren't doing any work though. Not on the wall itself.


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