The law is named after 17th century British physicist Robert Hooke, who sought to demonstrate the relationship between the forces applied to a spring and its elasticity. These can include anything from inflating a balloon and pulling on a rubber band to measuring the amount of wind force is needed to make a tall building bend and sway. This law has had many important practical applications, with one being the creation of a balance wheel, which made possible the creation of the mechanical clock, the portable timepiece, the spring scale and the manometer aka.
Also, because it is a close approximation of all solid bodies as long as the forces of deformation are small enough , numerous branches of science and engineering as also indebted to Hooke for coming up with this law. These include the disciplines of seismology, molecular mechanics and acoustics. Because no material can be compressed beyond a certain minimum size or stretched beyond a maximum size without some permanent deformation or change of state, it only applies so long as a limited amount of force or deformation is involved.
Together, they make it possible to deduce the relationship between strain and stress for complex objects in terms of the intrinsic materials of the properties it is made of.
For example, one can deduce that a homogeneous rod with uniform cross section will behave like a simple spring when stretched, with a stiffness k directly proportional to its cross-section area and inversely proportional to its length.
Any spring when compressed or extended almost perfectly conserves the energy applied to it. It relates to our eve ryday lives because without it, we would have a difficult time tweaking shocks on cars. We use cars everyday, and the shocks are what keep the ride smooth. The main component of car shocks are springs, and understanding how the spring will behave using hookes law is ideal for enhancing the technology. In this video I demonstrate hookes law by stretching out a piece of telephone chord.
The first time I stretch it, the wire returns back to its original shape. But when I stretch it out as hard as I can, the chord no longer completely returns to its original shape. This is because I have surpassed the chords limit of proportionality disrupting its internal structure. Hooke's law states that the amount of force needed to compress or extend an elastic object is proportional to the distance compressed or extended. British physicist Robert Hooke discovered this relationship around , albeit without math.
His findings were critical during the scientific revolution, leading to the invention of many modern devices, including portable clocks and pressure gauges.
It was also critical in developing such disciplines as seismology and acoustics, as well as engineering practices like the ability to calculate stress and strain on complex objects. This force can come from a squeeze, push, bend or twist, but only applies if the object returns to its original shape.
For example, a water balloon hitting the ground flattens out a deformation when its material is compressed against the ground , and then bounces upward.
The more the balloon deforms, the larger the bounce will be — of course, with a limit. At some maximum value of force, the balloon breaks. The broken water balloon will no longer go back to its round shape. A toy spring, such as a Slinky, that has been over-stretched will stay permanently elongated with large spaces between its coils. While examples of Hooke's law abound, not all materials obey it. For example, rubber and some plastics are sensitive to other factors, such as temperature, that affect their elasticity.
Calculating their deformation under some amount of force is thus more complex. Slingshots made out of different types of rubber bands don't all act the same. Some will be harder to pull back than others. The spring constant is a unique value depending on the elastic properties of an object and determines how easily the length of the spring changes when a force is applied.
Therefore, pulling on two springs with the same amount of force is likely to extend one further than the other unless they have the same spring constant. The larger the value of the spring constant, the stiffer the object and the harder it will be to stretch or compress.
The negative sign on the right side of the equation indicates that the displacement of the spring is in the opposite direction from the force the spring applies.
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