How Does Spring Force Affect Net Force in Physics?

AI Thread Summary
In the discussion about how spring force affects net force, a scenario is presented where a box is pressed against a wall with a spring attached. The forces involved include the push force and the spring force, which acts in the opposite direction. The net force is calculated by subtracting the spring force from the push force, leading to confusion about the negative sign indicating direction. It is clarified that the negative sign represents the restoring force's direction relative to displacement, not the spring constant itself. Visual aids, like sketches, are recommended to better understand the forces at play.
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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