Forces on a Spring: A Closer Look

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SUMMARY

The discussion clarifies the forces acting on a mass hanging from a spring. The downward force on the mass is its weight (mg), while the spring experiences an upward force from the ceiling. The confusion arises from the distinction between the forces acting on the mass and those acting on the spring. The force exerted by the spring on the mass is equal in magnitude and opposite in direction to the force exerted by the mass on the spring, but these forces act on different objects, leading to the mass's acceleration.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Basic knowledge of forces and acceleration
  • Familiarity with the concept of tension in springs
  • Knowledge of free-body diagrams
NEXT STEPS
  • Study Newton's Second Law of Motion in detail
  • Learn about Hooke's Law and spring constants
  • Explore free-body diagram techniques for analyzing forces
  • Investigate the dynamics of oscillating systems involving springs
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Students of physics, educators teaching mechanics, and anyone interested in understanding the principles of forces and motion in spring systems.

Wattever
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Sorry if this is a stupid question, I haven't studied mechanics in a while and suddenly I'm confused about this.

A mass m is hanging at the end of a spring. Forces on the mass: mg downwards and F upwards. Forces on the spring: mg downwards and a force upwards exerted on the spring by the ceiling. Is that correct? If so, where are the two forces that are equal in magnitude and opposite in direction? Shouldn't it be that if the mass pulls the spring with force P (=mg), the spring pulls the mass with an equal force P (so F=P)? I know this is not so though, since the mass does accelerate.
 
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The force on the mass from the spring is equal/opposite to the force on the spring from the mass. The forces are on the two separate objects, not the same object. The force on the spring is not mg, that is the force on the mass.
 

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