Physics Lesson 14 - Work Energy Theorem PDF
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Uploaded by InvigoratingCamellia
Saint Jude Catholic School
2022
Mr. Jerome Morales, Mr. Carl Fermil Aguinaldo
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Summary
This document is a physics lesson plan focused on the work-energy theorem for grade 10 students at Saint Jude Catholic School in Manila, Philippines. It includes diagrams, formulas, and explanations related to the topic. The lesson explores the relationship between work and energy changes.
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WORK-ENERGY THEOREM Mr. Jerome Morales Mr. Carl Fermil Aguinaldo GRADE 10 PHYSICS TEACHERS Copyright © 2022 Saint Jude Catholic School, Manila In the diagram above, the man is doing work on the boulder. By doing so, the boulder gains the ability to do work in everythin...
WORK-ENERGY THEOREM Mr. Jerome Morales Mr. Carl Fermil Aguinaldo GRADE 10 PHYSICS TEACHERS Copyright © 2022 Saint Jude Catholic School, Manila In the diagram above, the man is doing work on the boulder. By doing so, the boulder gains the ability to do work in everything that is on its way. Copyright © 2022 Saint Jude Catholic School, Manila When you do work on the bowstring, this bow gains the ability to do work on the arrow for shooting later on. Copyright © 2022 Saint Jude Catholic School, Manila When you do work on a box by lifting it and putting it on a certain amount of height from the floor, this box gains the ability to do work later on when it falls on to the ground. Copyright © 2022 Saint Jude Catholic School, Manila ENERGY The ability to do work is called ENERGY It is also expressed in Joules (J). Named after a physicist Professor James Prescott Joules who discovered that heat is related to mechanical energy which led to the Law of Conservation of Energy and the First Law of Thermodynamics. Worked alongside Prof. Lord Kelvin in developing a new thermometric scale "Kelvin" which is based on the ultimate freezing point. Copyright © 2022 Saint Jude Catholic School, Manila MECHANICAL ENERGY Mechanical energy is the energy (or ability to do work) of an object due to its... MOTION KINETIC ENERGY (KE) = ½ mv 2 POSITION GRAVITATIONAL POTENTIAL ENERGY (PE g ) = mgh Copyright © 2022 Saint Jude Catholic School, Manila WORK'S RELATION TO GRAVITATIONAL POTENTIAL ENERGY W = Fd PE g = mgh W = ∆ PE g = (mg) (h f – h o ) W = ∆ PE g = F g d W = ∆ PE g = (mgh f – mgh o ) THE CHANGE IN POTENTIAL ENERGY OF AN OBJECT (MOSTLY CAUSED BY CHANGE IN POSITION) IS EQUAL TO THE WORK DONE BY GRAVITY OF EARTH ON THE OBJECT. Copyright © 2022 Saint Jude Catholic School, Manila WHICH OF THE FOLLOWING OBJECTS WILL HAVE THE HIGHEST KINETIC ENERGY? LOWEST? EXPLAIN Copyright © 2022 Saint Jude Catholic School, Manila GRAVITATIONAL POTENTIAL ENERGY IS PATH- INDEPENDENT GRAVITATIONAL POTENTIAL ENERGY IS PATH-INDEPENDENT. THIS MEANS THAT IF ANOTHER OBJECT HAS TRAVELLED A GREATER DISTANCE, THEY WOULD STILL HAVE THE SAME AMOUNT OF GRAVITATIONAL POTENTIAL ENERGY AS LONG AS THEY HAVE THE SAME STRAIGHT- LINE MEASUREMENT RELATIVE TO THE GROUND. Copyright © 2022 Saint Jude Catholic School, Manila WORK'S RELATION TO MECHANICAL KINETIC ENERGY 2 V f = V o + 2ad 2 F = ma a = F/m V f 2 - V o 2 = 2ad V f 2 − Vo 2 = ad 𝟐 V f 2 − Vo 2 = (F/m) d 𝟐 ½ mv f 2 – ½ mv o 2 = Fd W = ∆𝐊𝐄 Copyright © 2022 Saint Jude Catholic School, Manila KINETIC ENERGY ALL MOVING OBJECTS HAS KINETIC ENERGY (KE). THIS CAN BE CALCULATED THROUGH THE EQUATION 1/2mv 2 THIS MEANS THAT IF AN OBJECT IS NOT MOVING, IT DOES NOT HAVE KINETIC ENERGY. THIS CAN ALSO BE CALCULATED THROUGH THE EQUATION: p 2/2m Where p is momentum and m is mass. Copyright © 2022 Saint Jude Catholic School, Manila WORK-ENERGY THEOREM W = ∆𝐊𝐄 = ∆𝐏𝐄g W = 𝐊𝐄f - 𝐊𝐄o = 𝐏𝐄(g)f - 𝐏𝐄(g)o THESE EQUATIONS SUPPORT THE IDEA THAT A NEGATIVE WORK MEANS A LOSS IN ENERGY OF A SYSTEM BY DOING WORK. Copyright © 2022 Saint Jude Catholic School, Manila TRY THIS! Mass of object Height Gravitation Potential Energy 10 kg 2m 700grams 1 km 10,000 mg 20 cm 1000 g 1 mile 99.99 cg 1 mm Copyright © 2022 Saint Jude Catholic School, Manila TRY THIS! Mass of object Velocity of Kinetic Energy movement 10 kg 3 m/s 700grams 9 kph 10,000 mg 100 m per minute 1000 g 3600 meters per hour 99.99 cg 10 m/s Copyright © 2022 Saint Jude Catholic School, Manila