1 / 11

Energy

Energy. Energy is defined as the ability (capacity) to do work Energy comes in many different forms Kinetic Energy: associated with motion Heat: associated with the speed of internal particles Chemical: bonds atoms together Electromagnetic: moving electric charges

darva
Télécharger la présentation

Energy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Energy • Energy is defined as the ability (capacity) to do work • Energy comes in many different forms • Kinetic Energy: associated with motion • Heat: associated with the speed of internal particles • Chemical: bonds atoms together • Electromagnetic: moving electric charges • Nuclear: in the atomic nucleus • Potential Energy: energy of position (energy at rest) Cover up

  2. Energy • The units of energy are joules • joules are also the same unit as work! (How Confusing!) • You can think of energy as stored work – that is ready to be released! • Energy cannot be created or destroyed – only changed from one type of energy to another!

  3. Kinetic Energy energy of motion All moving objects that have mass have kinetic energy. KE = 1/2 mv2 m - mass of the object in kg v - speed of the object in m/s KE - the kinetic energy in J

  4. Relationships • As mass increases, the KE increases • As speed increases, the KE increases • KE changes more with speed than with mass…WHY?

  5. Practice Problem 1 25.2 J • A model airplane with a mass of 0.350 kg is traveling at 12.0 m/s. The kinetic energy of the model airplane is __________.

  6. Practice Problem 2 6.4 m/s • A toy has a kinetic energy of 11.4 J. It has a mass of 0.56 kg. The velocity of the toy is _____.

  7. Kinetic Energy depends on two things: mass and speed Applying a force can give the cart speed, and therefore kinetic energy. A cart at rest has NO Kinetic energy Increasing the mass also increases kinetic energy because it takes even more force to push. Applying a greater force increases the speed and therefore the kinetic energy The amount of kinetic energy the cart has is equal to the amount of work you do to get the cart moving

  8. Work-Energy Theorem the work done on an object is equal to its change in kinetic energy The amount of kinetic energy an object has is equal to the amount of work you do to get the object moving

  9. A net force causes an object to change its KE because a net force causes an object to accelerate, and acceleration means a change in velocity, and if velocity changes, KE changes. Learn more about the Work-Energy Theorem here and here.

  10. Practice Problem 3 50 J • The engine on a 0.35 kg model airplane performs 50 J of work in accelerating the plane from rest. The kinetic energy of the model airplane is _______.

  11. Practice Problem 4 16.9 m/s • The engine on a 0.350 kg model airplane performs 50.0 J of work in accelerating the plane from rest. The final speed of the model airplane is _______.

More Related