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Chapter 7 : Conservation of Energy, CHEE ZI QING A20SC0043 - Coggle Diagram
Chapter 7 : Conservation of Energy
Conservative and Non conservative Forces
conservative = object moving any closed path is zero
conservative forces : Gravitational, Elastic, and Electric
non conservative forces : Friction, Air resistance, Tension
Potential Energy
can be transformed but cannot be destroyed or created
U=mgh (h=y2-y1) = (1/2)kx^2
when the object is droped U(potential energy) becomes K (kinetic energy)
F = -kx (hookes law about the spring compressed or stretch
Mechanical Energy and its Conservation
E (total mechanic energy) = K + U
Mechanical energy is conserve, so the intial=final
Problem Solving Using Conservation of Mechanical Energy
Using the formula of E = K+U
The Law of Conservation of Energy
Example of nonconservative or dissipative forces is friction, heat, Electrical/ Chemical energy......
total amount of energy remains constant
Energy Conservation with Dissipative Forces: Solving Problems
Power
P (Watt / Js^-1) = Force x velocity (Fv)
P = Energy / Time (E/t)
rate of work is done
Gravitational Potential Energy and Escape Velocity
Gravitational Force, F(Newton)= -GMm/R^2, negative sign indicate attractive
gravitational field strenght, g (ms^-2)= -GM/ r^2
Gravitational Potential energy, U(Joule)= -GMm/ r
Escape velocity, V = (2gR)^1/2
kinetic energy, K= GMm/ 2r
Potential Energy Diagrams:Stable and Unstable
CHEE ZI QING A20SC0043