Torque vs. Force

Main Difference

The main difference between Torque and Force is that the Torque is a tendency of a force to rotate an object and Force is a influence that causes an object to change motion.

• Torque

  Torque, moment, moment of force or “turning effect” is the rotational equivalent of linear force. The concept originated with the studies of Archimedes on the usage of levers. Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object. Another definition of torque is the product of the magnitude of the force and the perpendicular distance of the line of action of force from the axis of rotation. The symbol for torque is typically

  τ

  {displaystyle {boldsymbol {tau }}}

  , the lowercase Greek letter tau. When being referred to as moment of force, it is commonly denoted by M.

  In three dimensions, the torque is a pseudovector; for point particles, it is given by the cross product of the position vector (distance vector) and the force vector. The magnitude of torque of a rigid body depends on three quantities: the force applied, the lever arm vector connecting the origin to the point of force application, and the angle between the force and lever arm vectors. In symbols:

  τ

  =

  r

  ×

  F

  {displaystyle {boldsymbol {tau }}=mathbf {r} times mathbf {F} ,!}

  τ

  =

  ‖

  r

  ‖

  ‖

  F

  ‖

  sin

  ⁡

  θ

  {displaystyle tau =|mathbf {r} |,|mathbf {F} |sin theta ,!}

  where

  τ

  {displaystyle {boldsymbol {tau }}}

  is the torque vector and

  τ

  {displaystyle tau }

  is the magnitude of the torque,

  r is the position vector (a vector from the origin of the coordinate system defined to the point where the force is applied)

  F is the force vector,

  × denotes the cross product, which produces a vector that is perpendicular to both r and F following the right-hand rule,

  θ

  {displaystyle theta }

  is the angle between the force vector and the lever arm vector.The SI unit for torque is N⋅m. For more on the units of torque, see Units.

• Force

  In physics, a force is any interaction 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 newtons and represented by the symbol F.

  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.

• Force (noun)

  strength or energy as an attribute of physical action or movement

  “he was thrown backwards by the force of the explosion”

• Force (noun)

  an influence tending to change the motion of a body or produce motion or stress in a stationary body. The magnitude of such an influence is often calculated by multiplying the mass of the body and its acceleration.

• Force (noun)

  used with a number as a measure of wind strength on the Beaufort scale

  “a force-nine gale”

• Force (noun)

  coercion or compulsion, especially with the use or threat of violence

  “they ruled by law and not by force”

• Force (noun)

  mental or moral strength or power

  “the force of popular opinion”

• Force (noun)

  a person or thing regarded as exerting power or influence

  “he might still be a force for peace and unity”

• Force (noun)

  the powerful effect of something

  “the Committee accepted the force of this argument”

• Force (noun)

  an organized body of military personnel or police

  “a British peacekeeping force”

• Force (noun)

  troops and weaponry

  “a battle between the forces of good and evil”

  “left-wing guerrilla forces”

• Force (noun)

  the army, navy, and air force of a country.

• Force (noun)

  the police.

• Force (noun)

  a group of people brought together and organized for a particular activity

  “a sales force”

• Force (noun)

  a waterfall.

• Force (verb)

  make a way through or into by physical strength; break open by force

  “the back door of the bank was forced”

• Force (verb)

  drive or push into a specified position or state using physical strength or against resistance

  “thieves tried to force open the cash register”

  “Mark forced her arms back above her head”

• Force (verb)

  achieve or bring about (something) by effort

  “Sabine forced a smile”

  “they forced a way through the crowd”

• Force (verb)

  artificially hasten the development or maturity of (a plant).

• Force (verb)

  make (someone) do something against their will

  “the universities were forced to cut staff”

  “she was forced into early retirement”

• Force (verb)

  put out (a runner) by necessitating an advance to the next base when it is not possible to do so safely.