How Does Spring Force Affect Net Force in Physics?

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Homework Help Overview

The discussion revolves around the concept of spring force and its relationship to net force in a physics context, specifically involving a box and a spring attached to a wall. Participants are examining the implications of force equations and the directionality of forces involved.

Discussion Character

  • Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to analyze the net force acting on a box influenced by a spring force, questioning the interpretation of the negative sign in the force equation. Some participants clarify the meaning of the negative sign in relation to the restoring force and displacement.

Discussion Status

Participants are actively engaging with the original poster's question, providing clarifications regarding the direction of forces and encouraging further inquiry. There is an ongoing exploration of the concepts without a definitive consensus reached.

Contextual Notes

Participants suggest that visual aids, such as sketches, may enhance understanding of the problem setup and the directionality of forces involved.

Jaccobtw
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Homework Statement
Why is there a negative on the spring constant in this equation?: F = -kd
Relevant Equations
F = -kd
Let's say you have a box and there is a spring attached to it and the other end of the spring is attached to the wall. If you press the box towards the wall the spring presses back against the box with an equal force. F(push) = 20N, F(spring) = -kd. F(push) - F(spring) = F(net). Which is zero. However, because there is a negative, and because I am subtracting a negative, you get a much larger positive number of net force. Isn't this incorrect?
 
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The negative sign shows that the restoring force is in the opposite direction from the displacement (hence "restoring" force). The negative sign is associated with the displacement, not with the spring constant.

Does that help? :smile:
 
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BTW, keep asking good questions! :smile:
 
What also helps is a sketch of the situation, showing which way you consider positive...
 
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