What is Force: Definition and 1000 Discussions

In physics, a force is any influence that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newton (N). Force is represented by the symbol F (formerly P).
The original form of Newton's second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time. If the mass of the object is constant, this law implies that the acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object.
Concepts related to force include: thrust, which increases the velocity of an object; drag, which decreases the velocity of an object; and torque, which produces changes in rotational speed of an object. In an extended body, each part usually applies forces on the adjacent parts; the distribution of such forces through the body is the internal mechanical stress. Such internal mechanical stresses cause no acceleration of that body as the forces balance one another. Pressure, the distribution of many small forces applied over an area of a body, is a simple type of stress that if unbalanced can cause the body to accelerate. Stress usually causes deformation of solid materials, or flow in fluids.

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  1. MatinSAR

    Is the Work Done by a Variable Force Non-Conservative?

    Can anyone tell me if my answer is wrong ?!
  2. K

    I Force required to pull a cruise liner or cargo ship

    I was wondering how much force is required to pull the Cargo ship using a Kite as shown in below image and specifications given in table? This picture is taken from a seawing aka airseas website. I do not know the water / air / skin resistance values or coefficients for the cargo. All I know...
  3. paulimerci

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  4. O

    Converting Force Measurement to Pressure

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  5. Z

    Elbow Flexion Joint Reaction Force

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  6. arhg

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  7. A

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  8. G

    Analysis of a Figure to Calculate Force and Moment

    Figure: My attempt at a Solution: $$\overrightarrow{TFD}=TFD\dfrac{(-0,16\widehat{i}+0,11\widehat{j}-0,08\widehat{k})}{0,21}$$ View from above: We calculate ##D##: $$\sigma =90-\arctan \left( \dfrac{0,07}{0,240}\right)=73,74\, \textrm{º}$$ $$d=0,16\cdot \sin (\sigma)=0,1536\, \textrm{m}$$...
  9. samy4408

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  10. G

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  11. A

    Calculating Energy Dissipation for a Moving Object Using Integral Calculus

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  12. G

    Total force that a fluid exerts on a cylinder

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  13. J

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  14. G

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  15. S

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  16. FEAnalyst

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  17. dextercioby

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  18. Crunge

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  19. Idontknowhatimdoing

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  20. S

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  21. Elementard

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  22. P

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  23. theanswer2physicsisu

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  24. K

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  25. F

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  26. F

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  27. M

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  28. jaumzaum

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  29. Th3

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  30. S

    B Can gravitational force have influence on objects at infinitely long distances?

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  31. babaliaris

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    Hello! I'm trying to understand how this pendulum works. I found this video that explains how to calculate the T force from the rope. He uses the preservation of kinetic and potential energy in order to find the magnitude of the velocity and then using Newton's second law, he calculates the T...
  32. N

    I Exploring Magnetic Force: Magnet vs. Wires

    I understand the iron fillings become little magnets all pointing in the same north south direction similar to the spin aligned electrons in the permanent magnet. Similarly, a compass near a wire traces out the magnetic field lines ie North/South. My question is how do I reconcile the fact that...
  33. Z

    How to solve for face pressure on Roller 3 using the force pushing 1

  34. josephsanders

    I Tangential electric force at a surface

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  35. J

    Lorentz Force In Capacitors

    I am searching online for resources regarding studies done on the effect of the Lorentz force due to short circuit faults in capacitors. Although a DC-link capacitor only sees the ripple, there would be high current during a fault. Since F=(qE + JxB), I am curious what the effects of the high...
  36. W

    Tilting a 55 Gal Plastic Drum: Calculating Force Needed

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  37. Ahmed1029

    I Is electromotive force always equal to potential difference?

    In the case motional emf, there is a static magnetic field and a rectulgular loop that goes into the field region, then current is produced. There is no electric field, but there is an emf. However, Griffiths states that emf is equal to the potential difference between the source endpoints. But...
  38. E

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  39. Ahmed1029

    I Wave number, frequency, and velocity in dispersive waves

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  40. N

    Convert moment force at lever support

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  41. R

    Engineering Dynamics Problem with a Driving Force, 2 Wheels, a Spring and a Damper

  42. T

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  43. old fart

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  44. T

    How Is Cylinder Force Calculated to Rotate a Beam with a Horizontal Load?

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  45. Differentiate it

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  46. Jorrie

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  47. mopit_011

    B Equivalence of Frictional and Applied Force

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  48. U

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  49. MrSimp

    B Does Force Travel Faster Than Light?

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  50. C

    I Is there traction force between moving electrons & copper wire?

    Common sense: walking on road, there is traction between shoes & earth. I'm wondering: same thing for electric current's electrons & copper wire?
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