Pdf revisiting workenergy theorems implications researchgate. If the velocity of an object doubles, the kinetic energy increases by a factor of four. The two forms of mechanical energy are kinetic energy. Review the key concepts, equations, and skills for the work energy theorem. Net work and the work energy theorem we know from the study of newtons laws in dynamics. For example, on the uss constitution, a frigate used in the war of 1812, the cannons were 3 meters 3\mboxmeters 3 meters long, had a mass of 3000 kg 3000\mboxkg 3 0 0 0 kg, and could fire a 10 kg 10 \mboxkg 1 0 kg cannonball up to a kilometer away. Workenergy theorem boundless physics lumen learning. Kinetic energy is a simple concept with a simple equation that is simple to derive. Newtons second law provides us with one way to analyze this change of motion. Force and newtons laws of motion that net force causes acceleration.
The workenergy theorem applies to decreasing speed as well. The quantity latex\frac12mv2\\latex in the work energy theorem is defined to be the translational kinetic energy ke of a mass m moving at a speed v. The cannons on 19th century frigates were ponderous things. The net work done by the forces acting on the body is equal to the change in kinetic energy of the body. We will see in this section that work done by the net force gives a system energy of motion, and in the process we will also find an expression for the energy of motion. An unbalanced force applied to a particle will certainly change the particles state of motion. Use your understanding of the workenergy theorem to answer the following. The work energy theorem states that the work done by all forces acting on a particle equals the change in the particles kinetic energy. Start from the workenergy theorem, then add in newtons second law of motion. Application and practice questions the physics classroom. These simple ideas form the basis for our definition of work. However, we know from the definition of the derivative that.
This definition can be extended to rigid bodies by defining the work of the torque and rotational kinetic energy. The magnitude of the frictional force acting on the box. Showing top 8 worksheets in the category work and energy theorem problems. Workkinetic energy theorem practice problems online. In equation form, the translational kinetic energy, latex\textke\frac12mv2\\latex, is the energy associated with.
The work w done by the net force on a particle equals the change in the particles kinetic energy k e. Work and energy theorem problems worksheets teacher. We would like to suggest that you combine the reading of this page with the. Translational kinetic energy is distinct from rotational kinetic energy, which is considered later. Some of the worksheets displayed are work 5 work energy theorem, work 1 this is a lot of work, topic 5 work and energy, physics work work and energy, physics 1120 work energy solutions, kinetic energy the work energy theorem, name period date, problems work energy power 1 a kg mass. Notice that the definition of work involves both a force and a distance. Understand how the work energy theorem only applies to the net work, not the work done by a single source. The work down on the box by the frictional force, using the work energy theorem.
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