A free-body diagram shows all the forces acting upon a object. Use a box to represent the object and arrows to show the direction of the various forces. The relative size of the arrows can be used to indicate the magnitude of each force.
In a free-body diagram, gravity is shown as a downward arrow extending from the bottom edge of the box. If the object is sitting on a surface, the force of the surface pressing upward is called the normal force. The normal force is shown as an arrow pointing upward from the top edge of the box. If the object isn't moving, these two forces are usually the only ones shown.
If an object is in motion, friction usually becomes a factor. Friction is the force exerted by a surface as an object moves across it. Friction typically opposes forward motion, so it is shown as an arrow pointing in the opposite direction of motion. Air resistance is also a form of friction, but its effect is often negligible unless an object is in free fall or has a high surface area-to-mass ratio. Air resistance is usually shown as an arrow pointing upward from the top of a falling object.
Applied forces come in many forms. A person or a machine pushing an object in a particular direction is an example of an applied force. An applied force is usually shown by an arrow pointing in the direction of motion. Two opposing applied forces are shown as arrows on either side of the object pointing in opposite directions.
Tension is the force transmitted to an object through the pull of a string, a rope or a wire attached to it and pulled taut. If an object is hanging from a string, the force of tension is shown as an arrow pointing upward.
There are many different branches of modern physics, including astrophysics, nuclear physics, biophysics, mathematical physics, as well as optical and laser physics. Physics is the study of matter and energy and how they relate and interact through space and time, which also includes more theoretical branches such as high-energy experimental physics.Full Answer >
The “ABC of Physics” by Lev Okun is a brief guide to the fundamentals of modern physics. The book is used as guide for beginning physics students to understand the foundations of the subject.Full Answer >
As of 2014, the title "Father of Physics" has not been given to a single scientist. Isaac Newton, Albert Einstein, Galileo, Thales of Miletus and Aristotle, however, are some of the scientists who are greatly remembered for their noteworthy contributions and are among the great contenders for the title.Full Answer >
Physics has many real-life applications, and the principles of physics are at work any time someone drives a car, lifts something heavy or tries to stay warm in the winter.Full Answer >