Download Mechanical Energy

Mechanical Energy
Energy
Energy
drives all processes in all parts of Physics!
Objectives
the thing that enables us to do work
Identify types of energy
Define & calculate potential and
kinetic energy
Use conservation of mechanical
energy to solve for velocity
Kinetic Energy
Mechanical Energy
energy of motion
energy of position and motion in a system
Mechanical Energy = PE + KE
KE = 1 m v2
2
Unit: Joules (J)
Potential Energy
Potential Energy
energy of position
PE = mgh
m = .1 kg
Unit: Joules (J)
h = .2 m
1
Mechanical Energy
Conservation of Mechanical Energy
Conservation of Mechanical Energy
total energy is constant
BUT energy is transferred between forms (PE & KE)
m = .1 kg
h = .2 m
PE1 = .2 J
KE1 = 0
1
PE1 + KE1 = PE2 + KE2
2
Conservation of Mechanical Energy
1
PE1 = .2 J
KE1 = 0 PE3 = .1 J
KE3 = .1 J
3
PE2 = 0
h = .2 m
KE2 = .2 J
2
Conservation of Mechanical Energy
PE2 = 0
KE2 = .2 J
Conservation of Mechanical Energy
1
PE1 = .2 J
KE1 = 0
PE2 = 0
KE2 = .2 J
h = .2 m
2
Assignments . . .
­ Begin Chapter 8 Homework # 13 ­ 17 2