Download Torque Movie Hindi Mp4
Roseanne Devon
In physics and mechanics, torque is the rotational analogue of linear force.[1] It is also referred to as the moment of force (also abbreviated to moment). It describes the rate of change of angular momentum that would be imparted to an isolated body.
The concept originated with the studies by Archimedes of the usage of levers, which is reflected in his famous quote: "Give me a lever and a place to stand and I will move the Earth". Just as a linear force is a push or a pull applied to a body, a torque can be thought of as a twist applied to an object with respect to a chosen point. Torque is defined as the product of the magnitude of the perpendicular component of the force and the distance of the line of action of a force from the point around which it is being determined. The law of conservation of energy can also be used to understand torque. 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 displacement vector and the force vector. The magnitude of torque applied to a rigid body depends on three quantities: the force applied, the lever arm vector[2] connecting the point about which the torque is being measured to the point of force application, and the angle between the force and lever arm vectors. In symbols:
The term torque (from Latin torquēre, 'to twist') is said to have been suggested by James Thomson and appeared in print in April, 1884.[3][4][5] Usage is attested the same year by Silvanus P. Thompson in the first edition of Dynamo-Electric Machinery.[5] Thompson motivates the term as follows:[4]
Just as the Newtonian definition of force is that which produces or tends to produce motion (along a line), so torque may be defined as that which produces or tends to produce torsion (around an axis). It is better to use a term which treats this action as a single definite entity than to use terms like "couple" and "moment", which suggest more complex ideas. The single notion of a twist applied to turn a shaft is better than the more complex notion of applying a linear force (or a pair of forces) with a certain leverage.
Today, torque is referred to using different vocabulary depending on geographical location and field of study. This article follows the definition used in US physics in its usage of the word torque.[6]
In the UK and in US mechanical engineering, torque is referred to as moment of force, usually shortened to moment.[7] This terminology can be traced back to at least 1811 in Siméon Denis Poisson's Traité de mécanique.[8] An English translation of Poisson's work appears in 1842.
A force applied perpendicularly to a lever multiplied by its distance from the lever's fulcrum (the length of the lever arm) is its torque. A force of three newtons applied two metres from the fulcrum, for example, exerts the same torque as a force of one newton applied six metres from the fulcrum. The direction of the torque can be determined by using the right hand grip rule: if the fingers of the right hand are curled from the direction of the lever arm to the direction of the force, then the thumb points in the direction of the torque.[9]
It follows from the properties of the cross product that the torque vector is perpendicular to both the position and force vectors. Conversely, the torque vector defines the plane in which the position and force vectors lie. The resulting torque vector direction is determined by the right-hand rule.[10]
The traditional imperial and U.S. customary units for torque are the pound foot (lbf-ft), or for small values the pound inch (lbf-in). In the US, torque is most commonly referred to as the foot-pound (denoted as either lb-ft or ft-lb) and the inch-pound (denoted as in-lb).[14][15] Practitioners depend on context and the hyphen in the abbreviation to know that these refer to torque and not to energy or moment of mass (as the symbolism ft-lb would properly imply).
The construction of the "moment arm" is shown in the figure to the right, along with the vectors r and F mentioned above. The problem with this definition is that it does not give the direction of the torque but only the magnitude, and hence it is difficult to use in three-dimensional cases. If the force is perpendicular to the displacement vector r, the moment arm will be equal to the distance to the centre, and torque will be a maximum for the given force. The equation for the magnitude of a torque, arising from a perpendicular force:
For an object to be in static equilibrium, not only must the sum of the forces be zero, but also the sum of the torques (moments) about any point. For a two-dimensional situation with horizontal and vertical forces, the sum of the forces requirement is two equations: ΣH = 0 and ΣV = 0, and the torque a third equation: Στ = 0. That is, to solve statically determinate equilibrium problems in two-dimensions, three equations are used.
Steam engines and electric motors tend to produce maximum torque close to zero rpm, with the torque diminishing as rotational speed rises (due to increasing friction and other constraints). Reciprocating steam-engines and electric motors can start heavy loads from zero rpm without a clutch.
If a force is allowed to act through a distance, it is doing mechanical work. Similarly, if torque is allowed to act through an angular displacement, it is doing work. Mathematically, for rotation about a fixed axis through the center of mass, the work W can be expressed as
The unit newton-metre is dimensionally equivalent to the joule, which is the unit of energy. In the case of torque, the unit is assigned to a vector, whereas for energy, it is assigned to a scalar. This means that the dimensional equivalence of the newton-metre and the joule may be applied in the former, but not in the latter case. This problem is addressed in orientational analysis, which treats the radian as a base unit rather than as a dimensionless unit.[17]
The principle of moments, also known as Varignon's theorem (not to be confused with the geometrical theorem of the same name) states that the resultant torques due to several forces applied to about a point is equal to the sum of the contributing torques:
Torque can be multiplied via three methods: by locating the fulcrum such that the length of a lever is increased; by using a longer lever; or by the use of a speed-reducing gearset or gear box. Such a mechanism multiplies torque, as rotation rate is reduced.
We learned about force in our previous sessions. Torque is the tendency of a force that tends to cause rotation. Let us learn about torque, SI unit of torque, types of torque, examples of torque, and how torque is calculated.
Torque is the measure of the force that can cause an object to rotate about an axis. Force is what causes an object to accelerate in linear kinematics. Similarly, torque is what causes an angular acceleration. Hence, torque can be defined as the rotational equivalent of linear force. The straight line about which the object rotates is called the axis of rotation. In physics, torque is simply the tendency of a force to turn or twist. Different terminologies such as moment or moment of force are interchangeably used to describe torque. The distance of the point of application of force from the axis of rotation is sometimes called the moment arm or lever arm.
The drive shaft in a racing car accelerating from the start line exhibits dynamic torque because it must be producing an angular acceleration of the wheels, given that the car is accelerating along the track.
Now, from the above observation, we conclude that the torque produced depends on the magnitude of the force and the perpendicular distance between the point about which torque is calculated and the point of application of force. So, mathematically torque is represented as:
\(\beginarrayl\tau=Fr \sin \theta \endarray \)
where r is the length of the lever arm and θ is the angle between the force vector and the lever arm.
Some of the real-life examples involving torque are that of a see-saw or in automobiles engine. So next time when you go out just notice things that are working on the torque principle. We have just started our journey to learn rotational motion and translational motion. So sit back and enjoy learning with interesting video lessons.
Torque is the expression of a rotational or twisting force. The engines in vehicles rotate about an axis, thus creating torque. It can be viewed as the strength of a vehicle. Torque is what rockets a sports car from 0-60 kmph in seconds. Torque is also what powers big trucks hauling heavy loads into motion.
Torque is defined as the product of force and the perpendicular distance between the point of application of force and the pivot point. Torque in an electric medium means force experienced in an electric field. Similarly, torque in a magnetic medium is the force experienced in a magnetic field.
A force F is avector quantity,which means that it has both a magnitude anda direction associated with it. Thedirection of the forceis important because the resulting motion of the objectis in the same direction as the force.The product of the force and the perpendicular distance to thecenter of gravity for an unconfined object,or to the pivot for a confined object, is^Mcalled the torque or the moment.A torque is also a vector quantity and produces a rotationin the same way that a force produces a translation. Namely, an object atrest, or rotating at a constant angular velocity, will continue to do sountil it is subject to an external torque. A torque produces a changein angular velocity which is called an angular acceleration.
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