Presentation on theme: "In what forms, or types, does energy appear?"— Presentation transcript:
1In what forms, or types, does energy appear? Potential energy is often referred to as stored energy. It can come in many forms:Energy in food and gasolineGravitational, such as a tree about to fallnuclear-----energy in the nucleus of an atom that is released by fusion or fisionMechanical, such as energy that is stored in a spring or rubber band
2Kinetic energy is the energy an object possesses because of its motion: HeatLightSoundThermalElectricalRadiant
4What is energy (definition)? The ability to cause objects to change, move, or do workIn this activity, you will explore gravitational potential energy and kinetic energyHow can you transfer energy to the nail so that it drives into the foam block?
5Energy Transformation The change from one type of energy, such as potential to kineticEnergy TransferThe transfer of energy from one object to another
6Activity 54 Title: Drive a Nail Read pg. D-8 Problem: How does the height and mass of an object affect its gravitational potential energy?Hypothesis/Initial Thoughts:
7Why is it important to hold the rod in the same place every time? It is a variable that can be controlledWhat is the manipulated (or independent) variable or variables?What is the measured (or dependent) variable or variables?What are the energy transformations and transfers involved?Can I push the rod down each time? Why or why not?
8What do we know about:variable?Drop heightMass of object being droppedInitial depth of the nail in the foamAngle of dropStarting position of dropDropping rather pushing the rodNumber of drops to push the nail all way into the foamreproducibility?control?You must control all variables except the one you are testingWhat other variables are controlled?With your group do procedure steps 1-6. write your procedure on notebook paper.
9Questions to think about: What is the purpose?What variable are you testing?What variable will you keep the same?What is your control?Will you collect quantitative or qualitative data or both?
10Sample procedure:Stick the nail ________into the foam block so the nail head is _____ above the foam.Put the plastic tube _____________________________.Hold the long steel rod over the top of the tube so that its bottom is _____________________________________.Drop, don’t push the rod down the tube.Repeat steps 1-4 until ____________________________.Feel the nail and surrounding area for warmth.Record in a data table the number of times the rod was dropped.Gently remove the nail.Repeat steps 1-8 using the short steel rod.Repeat steps 1-8 using the long aluminum rod.Repeat steps 1-8 using the short aluminum rod.Repeat the experiment using the short plastic tube
11Table 1: Drive a Nail Data TubeRod (number of drops)Long steelShort steelLong aluminumShort aluminumLongShort
12Both variables cause the nail to be driven deeper into the foam What is the effect of changing two variables?Both variables cause the nail to be driven deeper into the foamThe combination of increased initial height and more mass results in more energy transferWith everything else being equal, an object with more mass has greater potential energy, likewise an object with greater height has more potential energyThe greater initial potential energy determines how much kinetic energy the rod has before hitting the nail
13Discuss potential vs kinetic energy Define gravitational potential energy in the context of the activityWhere did the rod have:the most potential energy?the least amount of potential energy?Define kinetic energy in the context of the activitythe most kinetic energy?the least amount of kinetic energy?
14Discuss potential vs kinetic energy The nail with the most potential energy before being dropped was transformed into the most kinetic energyGive an example of a real-world situation where gravitational potential energy is transformed to do work.What is the difference between gravitational potential energy and potential energy?