On the biomechanical analysis of the calories expended in a straight boxing jab

T I Zohdi1

  • 1Department of Mechanical Engineering, University of California, Berkeley, CA 94720-1740, USA zohdi@berkeley.edu.

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Free Body Diagrams: Examples

Solving problems that involve forces is easy using free-body diagrams. A free-body diagram is a sketch showing all the external forces that are acting on an object or system. The object or system is represented by a single isolated point (or free body). Only those forces acting on it that originate outside of the object or system—the external forces—are shown. The forces are represented by vectors extending outward from the free body. Imagine a person sitting on a chair. Here, the free-body...
Power Expended by a Constant Force00:57

Power Expended by a Constant Force

The relationship between work done and the time taken to do it can be explained using the concept of power. For example, several sprinters in a race may have the same velocity when they reach the finish line, therefore doing the same amount of work, but the winner does it in the least amount of time. Thus, power is defined as the rate of doing work. Since work can vary as a function of time, the average power is defined as the work done during a time interval, divided by the time interval.
Free-body Diagram01:28

Free-body Diagram

In mechanics, understanding the motion of objects is essential, and one tool that helps solve this problem is the free-body diagram. It is a simple but powerful graphical representation that succinctly represents all the forces acting on an object. A free-body diagram can represent a stationary or moving object, and is used in mechanics to explain the cause of an object's motion.
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Steps for Free-Body Diagram01:22

Steps for Free-Body Diagram

When it comes to studying the behavior of objects in mechanics, one of the most important tools available is the free-body diagram. Consider a simple example of a system of two blocks coupled by a massless string over a frictionless pulley. Block 1 is sliding over a table pulled by block 2 as block 2 falls under gravity.
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Work and Energy for Variable Forces01:10

Work and Energy for Variable Forces

When an object is acted upon by a variable force, the amount of work done and the change in energy of the object can be more complex to calculate compared to when a constant force is applied. Work is the product of force and displacement, while energy is the capacity of a system to do work. When a constant force is applied to an object, the work done can be calculated as the product of the force and the distance moved in the direction of the force. However, when a variable force is applied, the...
Kinetic Energy for a Rigid Body01:13

Kinetic Energy for a Rigid Body

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