What characteristics can you use to describe a force

Questions as broad as what is the origin of mass and what was matter like the first few seconds of our universe will be explored. This accelerator began preliminary operation in Tiny particles also have wave-like behavior, something we will explore more in a later chapter.

To better understand force-carrier particles from another perspective, let us consider gravity. The search for gravitational waves has been going on for a number of years. Almost years ago, Einstein predicted the existence of these waves as part of his general theory of relativity.

Gravitational waves are created during the collision of massive stars, in black holes, or in supernova explosions—like shock waves. These gravitational waves will travel through space from such sites much like a pebble dropped into a pond sends out ripples—except these waves move at the speed of light.

A detector apparatus has been built in the U. Each installation is designed to use optical lasers to examine any slight shift in the relative positions of two masses due to the effect of gravity waves. The two sites allow simultaneous measurements of these small effects to be separated from other natural phenomena, such as earthquakes.

Initial operation of the detectors began in , and work is proceeding on increasing their sensitivity. Earthquakes and other Earthly noises will be no problem for these monitoring spacecraft. LISA will complement LIGO by looking at much more massive black holes through the observation of gravitational-wave sources emitting much larger wavelengths. Three satellites will be placed in space above Earth in an equilateral triangle with 5,,km sides Figure 4.

The system will measure the relative positions of each satellite to detect passing gravitational waves. The launch of this project might be as early as Whether gravitational wave astrophysics will do that, only time will tell. Figure 4. Space-based future experiments for the measurement of gravitational waves. Each satellite of LISA will consist of a laser source and a mass. The relative motion of these masses will provide information about passing gravitational waves.

The ideas presented in this section are but a glimpse into topics of modern physics that will be covered in much greater depth in later chapters. Explain, in terms of the properties of the four basic forces, why people notice the gravitational force acting on their bodies if it is such a comparatively weak force. What is the dominant force between astronomical objects? Why are the other three basic forces less significant over these very large distances?

Give a detailed example of how the exchange of a particle can result in an attractive force. For example, consider one child pulling a toy out of the hands of another. Since the weak nuclear force acts at only very short distances, such as inside nuclei, where the strong and electromagnetic forces also act, it might seem surprising that we have any knowledge of it at all.

We have such knowledge because the weak nuclear force is responsible for beta decay, a type of nuclear decay not explained by other forces. What do your answers imply about the influence of the gravitational force on atomic nuclei? What is the ratio of the strength of the strong nuclear force to that of the electromagnetic force? Based on this ratio, you might expect that the strong force dominates the nucleus, which is true for small nuclei.

Large nuclei, however, have sizes greater than the range of the strong nuclear force. At these sizes, the electromagnetic force begins to affect nuclear stability. These facts will be used to explain nuclear fusion and fission later in this text. Skip to main content. Search for:.

Concept Connections: The Four Basic Forces The four basic forces will be encountered in more detail as you progress through the text. The gravitational force is defined in Uniform Circular Motion and Gravitation , electric force in Electric Charge and Electric Field , magnetic force in Magnetism , and nuclear forces in Radioactivity and Nuclear Physics. On a macroscopic scale, electromagnetism and gravity are the basis for all forces.

A force is a vector quantity. As learned in an earlier unit , a vector quantity is a quantity that has both magnitude and direction. To fully describe the force acting upon an object, you must describe both the magnitude size or numerical value and the direction. Thus, 10 Newton is not a full description of the force acting upon an object. In contrast, 10 Newton, downward is a complete description of the force acting upon an object; both the magnitude 10 Newton and the direction downward are given.

Because a force is a vector that has a direction, it is common to represent forces using diagrams in which a force is represented by an arrow. Such vector diagrams were introduced in an earlier unit and are used throughout the study of physics. The size of the arrow is reflective of the magnitude of the force and the direction of the arrow reveals the direction that the force is acting.

Such diagrams are known as free-body diagrams and are discussed later in this lesson. Furthermore, because forces are vectors, the effect of an individual force upon an object is often canceled by the effect of another force. For example, the effect of a Newton upward force acting upon a book is canceled by the effect of a Newton downward force acting upon the book.

In such instances, it is said that the two individual forces balance each other ; there would be no unbalanced force acting upon the book. Other situations could be imagined in which two of the individual vector forces cancel each other "balance" , yet a third individual force exists that is not balanced by another force. For example, imagine a book sliding across the rough surface of a table from left to right. A body projected making an acute angle with the ground changes its magnitude and direction of velocity continuously.

It may change the shape of an object. The shape of a sponge can be changed by applying force. By applying force on the plaster of Paris statues and models can be made.

When a balloon is filled with air its shape changes. Characteristics of Force:. State of a Motion of an Object:. The state of motion of an object can be described completely by its speed and the direction of motion. Types of Forces:. Depending upon the interaction between a force and an object, forces are classified as a Contact forces b Non-contact forces.

A force which can be applied only when it is in contact with an object is called a contact force. All mechanical forces are contact forces. A force which can be applied without any contact with two bodies is called a non-contact force e. Next Topic: Types of Forces. We have added some basic problems for the topic. Click the link below. Shortly we are going o add advanced level problems.

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