# The Physics of Scales

Length: 1176 words (3.4 double-spaced pages)

Rating: Excellent

#### Essay Preview

The Physics of Scales

To the dismay of some and a necessity for others, scales can be found about everywhere in today’s society. It never fails; if you go to the doctor you will step on the scale. They are at the grocery store, in most bathrooms and even in some of our favorite stores. Were we might even pay a quarter to have a machine tell us our weight, out loud. We as a society are obsessed with our weight. You’re asked for your weight when renewing your driver’s license. Every time you get in an elevator and see the little sign saying do not exceed *** lbs, the quarter-pounder with cheese and milkshake you ate for lunch, is brought back to your memory. A scale receives more mental and physical abuse than any other appliance that has ever been invented. All this abuse stems from a lesson each of use were taught at a young age, which is that we should always tell the truth. Well let’s look a little deeper into the scale and see the physics involved in how two different types’ of scales weigh objects.

There are two general kinds of scales. The first is a spring scale and the other type uses a load cell to electronically register a weight. Spring scales are the most common type of scale. The scale in your bathroom and those found in the produce department of your favorite grocery store are examples of spring scales.

This summer when you go to weigh that fat juicy watermelon, think about the mechanics of how the scale works. The basket is attached to a spring that stretches in response to the weight of the melon or other objects placed in it. The weight of the melon creates a downward force. This causes the spring to stretch and increase its upward force, which equalizes the difference between the two forces. As the spring is stretched, a dial calibrated to the spring registers a weight. When designing scales one needs to take into account that every spring has a different spring constant (k). Bloomfield (1997) defines k as “a measure of the spring’s stiffness. The larger the spring constant-that is, the stiffer the spring-the larger the restoring forces the spring exerts” (p. 82).
In analyzing the force associated with a certain spring, whether it is in you pen or under your truck, Hooke’s Law applies.

MLA Citation:
"The Physics of Scales." 123HelpMe.com. 18 Jan 2020
<https://www.123helpme.com/view.asp?id=32796>.

## Need Writing Help?

Get feedback on grammar, clarity, concision and logic instantly.

## Physics of Swimming Essay

- The study of physics and fluid dynamics in swimming has been a field of increasing interest for study in the past few decades among swimming coaches and enthusiasts. Despite the long history of research, the understanding of how to move the human body effectively through the water is still in its infancy. Competitive swimmers and their coaches of all levels are constantly striving for ways to improve their stroke technique and overall performance. The research and performances of today's swimmers are continuously disproving the beliefs of the past....   [tags: physics swim swimming]

Research Papers
1869 words (5.3 pages)

## The Physics of Music Essay

- ... As the sound is propagated outward, it is “spread” over a greater area. The minimum sound intensity that can be detected by the human ear (called the threshold of hearing) is about 10-2 W/m2. At a greater intensity of about 1W/m2, sound becomes painful to the ear. The frequency of a sound wave, seeming as pitch, is the number of compressions (or rarefactions) that pass a fixed point per unit time. The frequencies audible to the human ear range from approximately 20 hertz to 20 kilohertz. Intensity is the average flow of energy per unit time through a given area of the medium and is related to loudness, (Shipman-Wilson-Higgins, 2013)....   [tags: frequency, pitch, waves]

Research Papers
876 words (2.5 pages)

## Physics Investigation of Stopping Distances Essay

- Physics Investigation of Stopping Distances Aim === To investigate how a toy car's stopping distance is affected by its vertical height Hypothesis The greater an object's gravitational potential energy the longer it will take to cease all movement. This is because it will have more kinetic energy - and if we assume that the energy is removed at a constant rate by friction then the more kinetic energy an object has the longer it will continue moving Background knowledge This experiment will be looking at the transfer of energy from gravitational potential energy (gpe) to kinetic energy (ke) and the effect of friction on the loss of kinetic...   [tags: Papers]

Free Essays
737 words (2.1 pages)

## Essay about Motion: Physics and Seat Belts

- The scientific term of ‘motion’ is been one of the strangest phenomenon known in the history of physics. Since the end of the 17th century, the vast improvements in the technology and society have evolved the meaning of the word motion in terms of physics from ‘a simple movement’ to ‘a change in position, if acted upon by an unbalanced force’. In modern physics, motion is the change in position of an object with respect to its time and its reference point. Motion can be described as both scalar and vector quantity in relation to displacement, speed, direction, velocity, acceleration and time....   [tags: Position, Inertia, Seat Belts]

Research Papers
1591 words (4.5 pages)

## Essay on Physics of Sea Ice

- Sea ice is frozen sea water. Salt ions in the water complicate the growth of ice crystals, and makes sea ice much more dynamic than freshwater ice. Sea ice covers nearly 7% of the Earth's surface, has a huge effect on global climate, and is one of the largest, single biomes on Earth. Ice is the solid, crystalline form of water, which solidifies at 0ºC. Roughly 9 polymorphs of ice are defined, only one, however, occurs naturally on Earth. This common form of ice is known as ice 1h, and its lattice displays six-fold rotational symmetry....   [tags: physice ice sea]

Free Essays
872 words (2.5 pages)

## The Search for Large Extra Dimensions using Dijet Production from pp Collisions at 1.8 TeV

- The Search for Large Extra Dimensions using Dijet Production from pp Collisions at 1.8 TeV Abstract The search for extra dimensions has been a topic of great interest and has been investigated with a variety of methods and techniques of analysis.[1,2,3,4] The existence of Large Extra Dimensions (LED) can be determined given that (at ~ Mew or greater) gravity and its mediator, the graviton (spin 2), can access these extra dimensional manifolds. Atwood has developed a model using hadron colliders and the cross-sections for a 2 T 2 hadronic dijet process.[2] We propose to use this model and to make a best fit as well as to establish bounds using Ms, the Planck energy scale for when quan...   [tags: Physics Papers]

Free Essays
2900 words (8.3 pages)

## The Physics Of An Earthquake Essay

- Earthquakes are vibrations produced in the earth's outer layer, or crust, when forces pushing on a mass of rock overcome the friction holding the rock in place and blocks of rock slip against each other. The vibrations can range from barely noticeable to verry destructive. There are six types of shock waves. Two are classified as body waves which means they travel through the earth's interior and the other four are surface waves. The waves are changed by the rock types or formations they hit. Primary or compressional waves (P waves) send particles moveing back and forth in the same direction as the waves are traveling, secondary or transverse shear waves (S waves) send vibrations perpendicu...   [tags: essays research papers]

Free Essays
850 words (2.4 pages)

## Heat and Temperature Essay

- Relation of Heat and Kinetic Theory of Matter 1 The Kinetic Theory of Matter declares that particles of matter in all states are in vigorous motion. And this theory can help us predict heat transfer. Unmistakably the transfer of heat is the kinetic energy caused by the jittering of atoms or molecules in a substance. The faster the particles move, more heat is produced and the farther apart the molecules can spread. This theory explains heat transfer by conduction. Thermal energy flows from the warmer object and through the cooler one warming it up....   [tags: Physics]

Research Papers
880 words (2.5 pages)

## Essay on Nanophotonics

- Nanophotonics is the study of the effects of light at the nano-scale. This course on nanophotonics coupled with my previous courses on nanoscale circuit fabrication has taught me a great deal about the nano-scale and nano-electronics. Described in this paper are the uses of several nanophotonic principles which allow us to make and measure in scales never before possible. The first topic, plasmonics, is a physical phenomenon that allows us to measure small changes in thicknesses and also to see well below the diffraction limiting optical restrictions....   [tags: Physics]

Research Papers
1484 words (4.2 pages)

- Since the age of Aristotle, great minds have questioned the various natures of reality: how a concept works and how humans perceive it. The fundamentals of colour were one such mystery. As an unstable property, the secrets of colour have eluded philosophers, artists, and scientists for centuries, until 1666 when Sir Isaac Newton discovered the properties of light. Thanks to visionaries such as Newton, Hermann von Helmholtz, and Georges Seurat modern understanding of colour can be explained in a variety of manners and can now be categorized according to medium....   [tags: physics]

Research Papers
975 words (2.8 pages)

### Popular Essays

This law states that the restoring force exerted by an elastic object is proportional to how far it has been distorted from its equilibrium (F= -k*x). Bloomfield states that all things obey Hooke’s law, whether you’re pulling on a rope or jumping on the trampoline. As long as the force applied doesn’t exceed the elastic limit, it will return to its original position. Once the force crosses that limit permanent damage occurs (p. 83).

A bathroom scale works similar to the produce scale. The difference is in the use of multiple levers under the pad area to stretch a spring which in turn registers the weight of the object on the scale. Spring scales are quite simple, but still there are problems that can cause inaccurate readings. One of these becomes evident when weighing large objects, such as a baby elephant. Not only is it a large animal that might overload the scale. It is impossible to get all four of its feet on the same scale. If you take into account the objects center of gravity, you can use multiple scales and then add the outcomes for the total weight. If the center of gravity of an object is closer to one scale than the others, the closer scale will register more of the weight and could possibly be damaged.

Another problem in spring scales is motion; all springs exhibit harmonic motion properties. So in order to accurately read a scale you must wait until there is not any motion present. If you fail to wait for motion to stop than the spring is going to be stretching and relaxing, thus causing the dial to fluctuate as well. Other large objects that need weighed are semi-trucks. Instead of driving the semis’ onto multiple bathroom scales, other scale systems have been developed.

These systems include scales using load cells and other similar devices. Measurement Specialists is a company that specializes in load cells, at their website
www.measurespec.com a load cell is described as “a force transducer that takes force and registers it into an electrical signal” (p. 2). A load cell is made up of at least one strain gage, which can be set to measure either the compression of or the tension on the load cell. Multiple strain gages can be wired together to form a Wheatstone-bridge configuration. Which has four legs and as “the input current is applied to the bridge; the output becomes a voltage proportional to the force on the cell” (p. 3). At www.travel.howstuffworks.com this strain gage is described as “a thin wire that transmits electrical current and is attached to the beam, ring or column” (p. 1). As a force is applied to the cell, the strain gage is compressed or altered and thus changes the resistance in the wire. The signal from each cell is transmitted to a junction box that measures the variance in the current and calculates the weight the scale is supporting (p. 1).

Along these same lines there are other scales that use similar techniques. These techniques are listed on the previous website. They are the bending plate system and a piezoelectric system. The first uses metal plates with a wire gauge to measure the amount of stress it is under. Next, the piezoelectric system has sensors in a conducting material that detect changes in the voltage and displays the load on the system (p. 2).
In the process of deciding what type of scale one needs, there are three different ways to get the weight of a truck. These include:

1)One-axle, where the truck must slowly move a
crossed the scale to weigh each set of axles.

2)One-stop, which weighs the truck all at once, all
it needs to do is come to a stop.

3)Weigh-in-motion, which is exactly what the name implies. Some systems have even been installed on highways and monitor the weight as the trucks are at speed (www.travel.howstuffworks.com, p. 2).

The application that you are buying a scale for should influence what type of method you need.

So whether you are weighing a watermelon for the family-get-together or transporting watermelons to the grocery store. Next time you’re at or on a scale, you will be able to answer the question asked by many inquiring minds. How do scales work?

Works Cited

Bloomfield, L. (1997). How Things Work: The Physics of
Everyday Life. New York: Wiley & Sons.

Cutnell, J. D., & Johnson, K. W. (2001). Physics (5th ed.).
New York: Wiley & Sons.

How stuff works, (2003). How do truck weigh stations work?. Retrieved April 15, 2003, from http://travel.howstuffworks.com/question626.htm

Measurement Specialists. (2001, June). Load Cell Overview. Retrieved April 10, 2003, from http://www.measurespec.com/tips/principles.htm