What does y-intercept of a (a vs F) graph represent?

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The discussion centers on the interpretation of the y-intercept in a force vs. acceleration graph, where acceleration is plotted on the x-axis and force on the y-axis. The y-intercept of +7.74 indicates the force required to overcome static friction before any acceleration occurs, rather than representing kinetic friction. The slope of the graph, which equals the mass of the object, only applies when net external force is plotted against acceleration, not just applied force. This distinction is crucial for accurately analyzing the forces acting on an object at rest and in motion.

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efake
Hey! I was creating a force vs acceleration graph. acceleration is on the x-axis and force is on the y-axis. I got the slope and it was equal to the mass of the object. However, I got a y-intercept equal to +7.74(positive). What does this represent. Is this the friction or...?
 
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Let's think about this. So in a situation where an object is at rest on a surface with friction, you do apply a force, and nothing happens. Then you apply just the right amount of force to overcome static friction, so the object is now subject to kinetic friction.

So in static situation, the friction force is exactly equal to the applied force, and the object does not accelerate. In kinetic friction, the frictional force will be a constant {equal to mu*(normal force)}, but the slope (change in applied force divided by change in acceleration) would be equivalent to the mass of the object.

But there are other situations, where you apply a small force which causes nothing to happen. Think about a weight sitting on the ground, which you wish to pick up.
What happens when your force is less than the weight of the object? Then when your force is greater, what is happening?
 
efake said:
I got the slope and it was equal to the mass of the object
no it was not equal to the mass. you have plotted only 1 force vs acceleration. If you had plotted net external force , then slope would be equal to mass.
 

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