Embed Size (px)
Citation preview
ENERGY & WORK
Bill Nye Video WS - ENERGY
Energy makes things go!
Energy can be converted from one
form of energy to another!
Forms of Energy
▷ Kinetic▷ Potential▷ Chemical▷ Electrical▷ Thermal▷ Electromagnetic▷ Nuclear▷ Sound
Potential Energy
▷ Stored energy▷ Based on an
object’s position and mass
▷ PE = mgh▷ PE = weight*h
Kinetic Energy
▷ Moving energy▷ Amount of
kinetic energy depends on the object’s mass and speed
▷ KE = ½ mv2
Practice
A 15 kg bowling ball is sitting on a ledge 20 m high. What kind of energy does it have?
Calculate it!
Answer
A 15 kg bowling ball is sitting on a ledge 20 m high. What kind of energy does it have?
Potential
PE = (15 kg) (10 m/s2)(20 m)
PE = 3000 J
Practice
A 15 kg bowling ball is rolling down a hill at a speed of 4 m/s. What kind of energy does it have?
Calculate it!
Answer
A 15 kg bowling ball starts rolling down a hill at a speed of 4 m/s. What kind of energy does it have?
Kinetic
KE = ½ (15 kg)(4 m/s)2
KE = 120 J
Kinetic and Potential Energy WS
Conservation of Energy
Energy cannot be created or destroyed, only transformed from one form to another…
SO the total energy of a closed system should remain constant!
Total Mechanical Energy
The relationship between kinetic and potential energy…
TME = PE + KE
Roller Coaster Project
