Kinetic Energy

I. What is it?

    Energy due to an objects motion Is dependent upon  Velocity and Mass Equation for Kinetic Energy  KE = ½ (mass X velocity squared) OR  KE = ½ (mv 2 ) Kinetic energy depends more on velocity than mass

II. Types of Kinetic Energy

      Heat Light Sound Mechanical Electrical Examples of things which have kinetic energy:   Meteors and Comets Any sort of projectile (arrows, baseballs, darts)  Moving Water

Math Skills – Kinetic Energy #1

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http://video.google.com/videoplay?docid= 8566627404111495666&q=cheetah+running&total=413 &start=0&num=10&so=0&type=search&plindex=8 What is the kinetic energy of a 44 kg cheetah running at 31 m/s?

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Identify the known and unknown variables Unknown: KE Known: Velocity is 31m/s and weight is 44 kg Write down equation for KE Plus in numbers and solve KE = ½ (44 kg X 31m/s squared) KE = 21,142 Joules

Math Skills – Kinetic Energy #2

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http://www.youtube.com/watch?v=v3mP EVNVLA&feature=related At Cambridge University, a piano is dropped off of a dorm to symbolize the last day you are able to drop a class. Time how long it takes for the piano to hit the ground from 20 meters.

Determine the velocity. What is the kinetic energy of the piano (mass of 317 kg)?

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Identify the known and unknown variables Unknown: KE Known: 2.

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Write down equation for KE Plus in numbers and solve KE = ½ (317 kg X ____________squared) KE = _______________________

Math Skills – Kinetic Energy #3

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Refer to the previous video.

If the panda bear and bike travel at 9.26 m/s and have a kinetic energy of 682 Joules, what is the mass of the panda bear and bike?

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Identify the known and unknown variables Unknown: mass Known: Velocity is 9.26m/s and kinetic energy is 682 Joules.

Write down equation for KE Plus in numbers and solve 682 = ½ (mass X 9.26 m/s squared) Mass = 15.9 kg