What is Forces: 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. T

    Confused About Forces in Bearings: Getting Reactions in Axial Direction

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  2. S

    Statics: finding forces in frame

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  3. K

    What is the solution for finding F1 and F2 when angles are not equal?

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  4. S

    Physics Homework Question on Electrostatic forces

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  5. G

    Total forces acting downward on the plane

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  6. M

    Tensile and compressive forces

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  7. D

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  8. komarxian

    Skiing Up a Slope: Solving Work & Power Requirements

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  10. komarxian

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  11. Utilite

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  12. Firzan

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  13. W

    What are the negligible forces in the solar system besides gravity?

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  14. W

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  15. W

    How Does a Skydiver's Velocity Change with Distance After Parachute Deployment?

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  16. A

    Hydrostatic forces on a submerged curved surface question

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  17. M

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  18. J

    Forces on inclined plane question

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  19. D

    Need help using Method of Members to find reaction forces

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  20. S

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  21. O

    Calculating Forces in a Concrete Slab Supported by a Chain

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  22. TiernanW

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  23. A

    Right Hand Rule for Magnetic Forces.

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  24. Monsterboy

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  25. U

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  26. S

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  27. H

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  28. sander2798

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  29. KT KIM

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  30. PhiowPhi

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  31. T

    Finding the resultant of coplanar forces problem

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  32. Heres2hoping

    Calculating Tension in a Spider's Web: A Simple Forces Problem

    Homework Statement A spider builds a web using 4 strands as support. Strand 1: 21mN [20°E of N] Strand 2: 16mN [60°E of S] Strand 3: 18mN [40°W of S] Determine the force of tension in strand 4 assuming the web is stable. Homework Equations r(cosθ) - N/S components r(sinθ) - E/W components The...
  33. W

    Minimum Angle to Prevent Slip

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  34. **Mariam**

    Tension of a pendulum and force components

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  35. CollinsArg

    Vacuum in Torricelli Barometer and it's force?

    Hello! When a torricelli barometer is made there is a vacuum at the end of the top of the tube, does this vacuum exert a force to the water or mercury to go up? and how is that it can be a bigger vacuum depending on the air preassure? How does it exactly work? Thanks.
  36. REVIANNA

    Classical mechanics: forces on a pendulum

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  37. G

    Possible to derive pendulum velocity in a dynamic approach?

    Hi, Using conservation of energy $$m\cdot\ g\cdot\left(h_0-h\right)=\frac{1}{2}m\cdot\ v^2$$ it's easy to find the exact velocity of a pendulum $$v\left(h\right)=\sqrt{2g\cdot\left(h_0-h\right)}$$ at height ##h## above the minimum when it was let go from the inital height ##h_0##. Is it...
  38. Issy04

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  39. R

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  40. H

    Equilibrium of Forces Paradox

    Hi ! So a friend and I were solving some mechanics problems in class today. And we came across a pretty funny mathematical paradox. So basically we tackled the problem in different ways...but we ended up with different equations...and none of us could prove the other wrong ! So here goes... The...
  41. E

    Question regarding Earth, Moon and tidal forces

    Homework Statement If the distance between the Earth and the Moon doubled, by what factor would the tidal forces felt on Earth decrease by? Homework Equations Not sure if there are any relevant equations F = GM1M2 / r∧2The Attempt at a Solution [/B]G = 1/d^2, if d is doubled, then G =...
  42. O

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    Equations I used: Fty = Ft(sinθ) Ftx = Ft(cosθ) My attempt: I drew a free body diagram that looked like this (the red are just components of the tension, I know they wouldn't usually be included on a free body). Finding Magnitude of Tension: Fg = 516 (I gathered from the problem) Fg = Fty...
  43. R

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  44. M

    Need help figuring out this forces question

    Homework Statement the question states: "wo forces act on an object at an angle of 75 degrees. One force is 195N. the net force it 225n. determine the second force that it makes with the net force" Homework EquationsThe Attempt at a Solution I tried finding the second force by finding the two...
  45. L

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    From my research and understanding of roller coasters, their speed is mainly impacted by the force of gravity and it works on the basis of potential energy build up into kinetic energy. Therefore, my question surrounds the idea of safe speeds on coasters. Because a roller coaster car is only...
  46. K

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  47. gulfcoastfella

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  48. galadriel3562

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  49. mattbeatlefreak

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  50. mcaay

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