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Unit 2: Momentum & Energy - Coggle Diagram
Unit 2: Momentum & Energy
Lesson 1 Applications of Newtons Second Law
F = ma
Dynamics and kinematics
Find the acceleration.
Use the acceleration to calculate some other property of motion.
G.R.A.S.P
Net Force
Free-body diagram
Lesson 2 Applications of Newtons Third Law
For every action there is an equal and opposite reaction.
Tention
Atwood’s Machine
Two masses connected by a strong light string that are hung over an ideal pulley (light and frictionless).
Notice the direction of acceleration and tension.
Objects connected at an angle
Free-body diagram
Lesson 3 Momentum and Collisions
Momentum
The tendency of objects to keep going in the same direction with the same speed.
A property of moving matter.
p = mv
The law of conservation of momentum
The total momentum of the system cannot change when a system of interacting objects is not influenced by outside forces.
Collisions
Momentum is conserved separately in the x and y directions.
Elastic collision - m1v1+m2v2=m1v3+m2v4
Inelastic collsion - m1v1+m2v2=(m1+m2)v3
Lesson 4 Kinetic and Potential Energy
Work
W = Fd
Notice the angle.
Positive work.
Work done on a system that adds energy to the systems.
Negative work.
Work done on a system in which energy is removed from the system.
Kinetic Energy
W = ∆Ek
Potential Energy
Ep = mgh
W = mg∆h2 – mg∆h1 = ∆Eg
Elastic potential energy
Power
P = w/t
P = E/t
Lesson 5 Energy transformations
Conservative vs. Non-Conservative
Conservative Force
The work done on an object is independent of the pathway taken by the object.
Non-Conservative Force
the work done on an object is dependent on the pathway taken by the object.
Types of Collisions
Elastic Collision: Total kinetic energy is conserved
Inelastic Collision: The total kinetic energy is not conserved. Some of the kinetic energy is lost
Completely inelastic collisions: The two objects stick together after the collision
Law of Conservation of Mechanical Energy
The energy remains the same as before a process is done as with after a process is done.
Potential Energy vs. Kinetic Energy
Total Energy = mgh + 1/2mv2
Total energy = 1/2kx2 + 1/2mv2
Conservation of Energy
Total Energy - Wnc = (KEfin – KEinit) + (PEfin – PEinit)
Non-conservation of Energy
W = Wnc + Wc = KEfin - KEinit
Jerry Zou
