Propelling My PowerPropelling My Power

My Power lasts infinitely My Power lasts infinitely

Objective:Objective: Apply the conservation of Apply the conservation of

mechanical energy to different mechanical energy to different situations.situations.

Solve problems on kinetic and Solve problems on kinetic and potential energypotential energy

Do you want to know more about…..

Potential Energy

M.E.

Kinetic Energy

Potential EnergyPotential Energy

The potential energy (PE) is The potential energy (PE) is attributed to the height (h) if the mass attributed to the height (h) if the mass (m) is constant.(m) is constant.

If h is increase then PE will increase, If h is increase then PE will increase, and when h is decrease PE will and when h is decrease PE will decrease.decrease.

PE = mgh, g=9.8m/sPE = mgh, g=9.8m/s22

Kinetic EnergyKinetic Energy

The kinetic energy (KE) is attributed to the The kinetic energy (KE) is attributed to the motion (speed or velocity) of an object.motion (speed or velocity) of an object.

The formula in finding the KE of an object is The formula in finding the KE of an object is KE=KE=½mv½mv22

V=speed or velocity of an objectV=speed or velocity of an object M=mass of an object M=mass of an object

Sample problem on Potential EnergySample problem on Potential Energy

What is the potential energy of a 5kg ball that What is the potential energy of a 5kg ball that is 6m high from the ground?is 6m high from the ground?

Given: mass(m)=5kg,acceleration due to Given: mass(m)=5kg,acceleration due to gravity(g)=9.8m/sgravity(g)=9.8m/s22, height(h)=6m, height(h)=6m

Solution:Solution: PE=mghPE=mgh =(5kg)(9.8m/s=(5kg)(9.8m/s22)(6m))(6m) =294kg.m=294kg.m22/s/s22 or 294Joules(J,unit of or 294Joules(J,unit of

potential energy)potential energy)K.E.

Sample Problem on Kinetic EnergySample Problem on Kinetic Energy

If a 0.2kg toy cart moves at a speed of 2m/s,calculate its If a 0.2kg toy cart moves at a speed of 2m/s,calculate its kinetic energy.kinetic energy.

Given: m=0.2kgGiven: m=0.2kg v=2m/sv=2m/s Find KE.Find KE. SolutionSolution KEKE=½mv=½mv22

=½(0.2kg)(2m/s)=½(0.2kg)(2m/s)22

=½(0.2kg)(4m=½(0.2kg)(4m22/s/s22)) =0.4Joules=0.4Joules =0.4J=0.4J

ExercisesExercises

Potential EnergyQuiz

Kinetic EnergyQuiz

AssignmentAssignment

References:References:

1.Physics, Vol 1 By: Avenido,et al1.Physics, Vol 1 By: Avenido,et al Science and Technology of today By:Dizon,et Science and Technology of today By:Dizon,et

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