Work Done by a Constant Force

Contact forces are forces that occur when two interacting items are believed to be physically engaging one another. Forces are defined in newtons (N or kgm/s²), while displacements are expressed in metres (m).

Despite their great physical separation, the sun and the planets, for example, have a gravitational pull towards one another. There is also a gravitational force between you and the Earth when your toes leave the ground and you’re no longer in physical interaction with it. Despite the electric force’s short spatial separation, the protons in an atom’s nucleus and the electrons outside the nucleus sense an electrical attraction towards each other. For example, two magnets can exert magnetic force on each other despite being separated by only a few centimetres. Force is usually depicted using diagrams in which an arrow represents the force. A downward force presses on a book, for instance. In such cases, it is argued if the integration of the variable force and the opposing forces balanced each other, the book would not be subjected to an uneven force.

Constant Force

A constant force is one that does not change in regard to the time when applied to an object. 

A constant force assists in maintaining an object’s steady speed and enables uniform motion. A force given to a stationary object is also considered to be constant if it aids in maintaining its balance. Basically, a constant force is a force that tends to act on an item for an infinitely long period of time, assuming the physical conditions stay constant. When the force is constant, the work done by the constant force is equal to the product of the force and the distance travelled in the force’s direction.

If a body is held on a frictionless surface and a force of a constant magnitude of 10 N acts on it, the body will finish a distance of 5 metres due to the action of the forces, and the formula of the work done will be given as W = F x s  ( W= work done, F = Force applied, s = distance travelled)

Positive Work

Positive work is done when a force displaces an object in the desired direction (direction in which force is applied).

The motion of a ball descending towards the earth with the displacement of the ball in the direction of gravity is an example of this type of work. 

Negative Work

Work is considered to be negative when the force and the displacement are in opposite directions. For instance, if a ball is thrown up, its displacement will be upwards, while the force due to gravity will be downwards. The work performed by the force on the object is 0 if the paths of the force and the displacement are vertical to each other. When we push forcefully against a wall, for example, the force that we are putting on the wall produces no work as the wall’s displacement is d = 0. Our muscles, on the other hand, use our internal energy in this procedure, and as a result, we get exhausted. 

Examples of Constant Force

Some examples of constant forces are gravity, the force of friction, upthrust, pendulum, and many more. 

Gravity pulls on an object regardless of the passage of time, and that is why it is classified as a constant force. 

Friction is a force that is produced in response to an object’s motion. It tends to counter that particular body’s movement. The amount of friction applied to an object is independent of time. At all times, the intensity of friction is maintained at a constant level. As a result, friction is a good illustration of a force applied. 

The force exerted by the fluid on an object that comes into touch with it is known as buoyant force. As long as the object remains in contact with the fluid, it experiences the impact of buoyancy. Also, the intensity of the force applied by it does not change. As a result, upthrust is always present. 

Another example of constant force is cycling. While cycling, a person exerts force which makes the cycle constantly work. This makes it work constantly, hence making cycling a constant force. 

Hydrostatic force can be determined as a constant force, unlike buoyancy. Hydrostatic force exerts force on the object from each side of the respective object, and in the case of buoyancy, the force is exerted only in the upward direction. Therefore, hydrostatic force is also classified as constant force.  

Hooke’s Law 

Hooke’s law is Fs = kx, where k is a constant factor inherent in the spring, and x is modest compared to the entire possible deformation of the spring. 

This law was named after British physicist Robert Hooke who lived in the 17th century. In 1676, he originally presented the law as a Latin anagram. In 1678, he revealed the answer to his riddle. In his 1678 essay, Hooke claims to have been cognizant of the law since 1660. 

In many other circumstances where an elastic body is deformed, such as a breeze coming on a tall building or a musician strumming a guitar string, Hooke’s equation stands (with some level). A linear-elastic or Hookean body or substance is one for which this equation can be accepted.

The genuine reaction of springs and other elastic bodies to applied forces is only approximated by Hooke’s law, which is a first-order linear approximation. After the elastic limits are exceeded, several materials diverge noticeably from Hooke’s rule. 

Hooke’s law is generalised in the contemporary theory of elasticity, which states that the strain (deformation) of an elastic item or substance is proportional to the stress applied to it. However, since general stresses and strains might have numerous independent components, the “proportionality factor” may have been a linear map (a tensor) that could be described by a matrix of real numbers rather than just a single legitimate number.

Hooke’s law, in its most general form, allows you to determine the relationship between strain and stress for complicated objects based on the intrinsic qualities of the materials that they are composed of. The law is typically observed in objects that swiftly restore their original shape after being deformed by a force, with the molecules or atoms of their substance reverting to a state of stable equilibrium.

The law only applies to particular materials and loading circumstances. In most engineering applications, steel behaves linearly elastically, and Hooke’s law holds true across its elastic range (i.e., for stresses below the yield strength). The law is only applicable for a fraction of the elastic range in various other materials, such as aluminium. Proportional limit stress is calculated for these materials below which the linear approximation errors are minimal.

Rubber is considered a “non-Hookean” material since its elasticity is stress-dependent and temperature and loading rate sensitive.

Conclusion

There are several other types of forces present in the universe which have been described by physicists and there are unique ways to understand them individually. Forces are everywhere around us, and with the growth in education, it is possible that we may get to know about some new forces in the future and understand our surroundings in a better manner. There are numerous applications of forces in our daily life, such as force torque sensors that are widely used in industries for mechanical purposes, and several force-controlled appliances are made to ease daily life activities.