Understanding the Relationship Between Force, Momentum, and Impulse

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SUMMARY

The discussion clarifies the relationship between force, momentum, and impulse, emphasizing that force (F) is the rate of change of momentum (P) over time. The equations F = ma and P = mv are foundational, linking acceleration to momentum through time. The concept of impulse is introduced as a force acting over a time interval, which explains why an egg dropped on a pillow does not break, as the increased time interval reduces the force experienced by the egg compared to dropping it on concrete.

PREREQUISITES
  • Understanding of Newton's Second Law (F = ma)
  • Familiarity with the concepts of momentum (P = mv)
  • Basic knowledge of calculus, particularly derivatives
  • Concept of impulse and its relation to force and time
NEXT STEPS
  • Study the derivation of F = dp/dt in detail
  • Explore the concept of impulse and its applications in real-world scenarios
  • Learn about the conservation of momentum in collisions
  • Investigate the role of time intervals in force application and impact scenarios
USEFUL FOR

Physics students, educators, and anyone interested in the dynamics of motion and forces, particularly in understanding how force, momentum, and impulse interact in various physical situations.

zeshkani
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Is force related to Momentum or momentum to force in anyway
F=ma and P=mv
 
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Yes, the link between the two is time. Essentially, force is applied over time to change an objects momentum.

Because F = m a, and a =\Deltav / t
then F = m v/t
As you said P = mv so we get
F = P/t or P = Ft
 
With calculus, the equations become more instantaneous and exact:

F=ma=m(dv/dt)=dp/dt-v(dm/dt).

If dm=0 (for instance, not a rocket) then:

F=dp/dt
 
thx a lot :)
 
Also, do you know the concept of Impulse? It has the same dimensions of momentum, but is more precisely defined as a Force acting over a certain amount of time. That's why when you drop an egg on a pillow, it will not break, but when you drop an egg on concrete, it will. Because the egg has some mass m and velocity v, and therefore some momentum p = mv, this momentum is numerically equal to the reactive force of the ground(or pillow) multiplied by the time interval it spends on that respective surface.

The pillow cushions the fall and therefore increases the time interval, in effect decreasing the force and keeping the egg from breaking. When you drop it on the concrete, the time interval is very short, and so the force on the egg is large (which is why it breaks).
 

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