Summary

This document is a physics lesson plan for secondary school students about work, energy, and power, with sample problems. The document contains learning objectives, essential questions, formulas, and examples of calculations.

Full Transcript

HOLY SPIRIT ACADEMY OF MALOLOS, INC. Bagong Bayan, City of Malolos, Bulacan LESSON 2 WORK, ENERGY, & POWER Ms. Juni Francia WORK, ENERGY, AND POWER ARE KEY PHYSICS CONCEPTS. Work occurs when a force moves an object, while energy is the ability to do work. Power measures how...

HOLY SPIRIT ACADEMY OF MALOLOS, INC. Bagong Bayan, City of Malolos, Bulacan LESSON 2 WORK, ENERGY, & POWER Ms. Juni Francia WORK, ENERGY, AND POWER ARE KEY PHYSICS CONCEPTS. Work occurs when a force moves an object, while energy is the ability to do work. Power measures how quickly work is done. LEARNING OBJECTIVES 1. Define work in the context of physics. 2.Define power and its units of measurement 3.Identify and classify different forms of energy. 4.Recognize the importance of conserving energy resources. 5.Calculate the work, power and energy TRUTH IN LOVE ESSENTIAL QUESTIONS When is work done? How can work cause energy to change from one form to another? How much power can you deliver? TRUTH IN LOVE WORK WHEN IS WORK DONE? Work is done when a force acts on an object, causing it to move in the direction of the force over a certain distance. TRUTH IN LOVE FORMULA Work (W) = Force (F) x Distance (d) W is work (joules, J) James Prescott Joule was an English physicist and mathematician. He is most famous for his discovery that heat is a form of energy. TRUTH IN LOVE FORMULA Work (W) = Force (F) x Distance (d) W is work (joules, J) F is force (newtons, N) d is distance (meters, m) TRUTH IN LOVE SAMPLE PROBLEM PROBLEM NO. 1 A worker pushes a crate with a force of 150 N across a floor for a distance of 5 meters. Calculate the work done by the worker. TRUTH IN LOVE SAMPLE PROBLEM PROBLEM NO. 1 Given: ⚬ Force (F) = 150 N ⚬ Distance (d) = 5 m Required: ⚬ Work (W) Equation: ⚬ W=F*d Solution: ⚬ W = 150 N * 5 m ⚬ W = 750 Nm or 750 Joules (J) Answer: ⚬ The work done by the worker is 750 Joules. TRUTH IN LOVE SAMPLE PROBLEM PROBLEM NO. 2 A worker pushes a crate with a force of 50 Newtons across a warehouse floor. If the worker does 250 Joules of work, how far did the crate move? TRUTH IN LOVE SAMPLE PROBLEM PROBLEM NO. 1 Given: ⚬ Work done (W) = 250 Joules ⚬ Force (F) = 50 Newtons Required: ⚬ Distance (d) Equation: ⚬ W=F*d Solution: ⚬ d=W/F ⚬ d = 250 Joules / 50 Newtons ⚬ d = 5 meters Answer: ⚬ The distance covered by the crate is 5 meters. TRUTH IN LOVE ENERGY HOW CAN WORK CAUSE ENERGY TO CHANGE FROM ONE FORM TO ANOTHER? Energy is essentially the capacity to do work. It's like the fuel that powers actions and changes in the world around us. TRUTH IN LOVE TYPES OF ENERGY MECHANICAL ENERGY This is the energy associated with motion and position. It's divided into: ⚬ Potential Energy and Kinetic Energy TRUTH IN LOVE TYPES OF MECHANICAL ENERGY POTENTIAL ENERGY Stored energy due to an object's position or condition. TRUTH IN LOVE TYPES OF POTENTIAL ENERGY GRAVITATIONAL POTENTIAL ENERGY Depends on mass, gravity, and height. (PE = mgh) TRUTH IN LOVE TYPES OF POTENTIAL ENERGY ELASTIC POTENTIAL ENERGY Stored in objects that can be stretched or compressed. (PE = 1/2 kx²) TRUTH IN LOVE TYPES OF MECHANICAL ENERGY KINETIC ENERGY Energy possessed by an object due to its motion. KE = 1/2 mv²) TRUTH IN LOVE TYPES OF ENERGY OTHER FORMS Other Forms: Heat, light, sound, electrical, chemical, and nuclear energy. TRUTH IN LOVE WORK ENERGY THEOREM W = KE - KE0 The work-energy theorem states that the work done on an object equals the change in its kinetic energy (W = KE - KE0). TRUTH IN LOVE POWER THE RATE AT WHICH WORK IS DONE. TRUTH IN LOVE POWER P = W/t (Power = Work / Time) Unit of Power (Watt) Named for James Watt, the British inventor of an engine that helped power the Industrial Revolution TRUTH IN LOVE POWER P = Fv (Power = Force x Velocity) In the straightforward cases where a constant force moves an object at constant velocity TRUTH IN LOVE SAMPLE PROBLEM PROBLEM NO. 1 A worker does 250 Joules of work in 5 seconds while pushing a crate across the floor. What is the power output of the worker? TRUTH IN LOVE SAMPLE PROBLEM PROBLEM NO. 1 Given: ⚬ Work done (W) = 250 Joules ⚬ Time (t) = 5 seconds Required: ⚬ Power (P) Equation: ⚬ P=W/t Solution: ⚬ P = 250 Joules / 5 seconds ⚬ P = 50 Watts Answer: ⚬ The power output of the worker is 50 Watts. TRUTH IN LOVE SAMPLE PROBLEM PROBLEM NO. 2 A car exerts a force of 5000 N to maintain a constant speed of 20 m/s. Calculate the power output of the car. TRUTH IN LOVE SAMPLE PROBLEM PROBLEM NO. 2 Given: ⚬ Force (F) = 5000 N ⚬ Velocity (v) = 20 m/s Required: ⚬ Power (P) Equation: ⚬ P = Fv Solution: ⚬ P = (5000 N)(20 m/s) ⚬ P = 100,000 Watts TRUTH IN LOVE SCAFFOLDING QUESTIONS How is power related to work? What factors affect the power output of a machine? How can we calculate the power used by a light bulb? TRUTH IN LOVE ASSIGNMENT PREPARE FOR LABORATORY ACTIVITY 2 FOR NEXT WEEK VARIOUS OBJECTS WITH DIFFERENT MASSES (E.G., BALLS, BOOKS, MARBLES) RAMP OR INCLINED PLANE (E.G., 2 SCIENCE BOOK) STOPWATCH METER STICK OR RULER SPRING SCALE RUBBER BAND OTHER MATERIALS AS NEEDED (E.G., FLASHLIGHT, BATTERY) TRUTH IN LOVE CONCLUSION applying knowledge of power responsibly, considering its impact on individuals and the environment. TRUTH IN LOVE TRUTH IN LOVE REFERENCES Ferriols-Pavico, J. ,Morales-Ramos A., Bayquen A. , Silverio A. , Ramos J.. (2020). Exploring life through science series : the new grade 8. Phoenix Publishing House. TRUTH IN LOVE

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