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| =Objectives= | | =Objectives= |
| + | #To study the motion of a simple pendulum |
| + | #To observe the different factors on which the motion of a simple pendulum depends |
| + | #Develop an understanding that gravity is a conservative force |
| + | |
| + | ==== Pre-requisites ==== |
| + | |
| + | Availability of computer, projector, simulation |
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| + | |
| + | Prior discussion on forms of energy |
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| + | ==== Method: ==== |
| + | |
| + | Use the PhET simulation Pendulum Lab. |
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| + | |
| + | For this we will need to open an application called PhET on the |
| + | computer. You can find PhET under Applications> Education> |
| + | Science. PhET is an educational resource that contains computer |
| + | demonstrations of experiments and activities. When we click on Play |
| + | with sims – it will open simulations in various subjects. We will |
| + | click on Physics and scroll down to the simulation on Pendulum Lab. |
| + | |
| + | |
| + | When we want to open a simulation, we click on the green |
| + | rectangle which says “Run Now”. |
| + | |
| + | |
| + | After running the simulation show the following video |
| + | [[/home/ranjani/Desktop/Conservation of energy/Conservation of Energy in simple pendulum.VOB]] |
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| + | ==== Discussion question for activity ==== |
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| + | '''Questions:''' |
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| + | Screenshot #2 |
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| + | '''Questions:''' |
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| + | Screenshot #3 |
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| + | '''Questions:''' |
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| + | '''Screenshot #4''' |
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| + | '''Questions:''' |
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| + | ==== Notes (optional) ==== |
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| + | The motion of a pendulum is a classic example of mechanical energy |
| + | conservation. A pendulum moves it sweeps out a circular arc, moving |
| + | back and forth in a periodic fashion. Neglecting air resistance |
| + | (which would indeed be small for an aerodynamically shaped bob), |
| + | there are only two forces acting upon the pendulum bob. One force is |
| + | gravity. The force of gravity acts in a downward direction and does |
| + | work upon the pendulum bob. However, gravity is an internal force (or |
| + | conservative force) and thus does not serve to change the total |
| + | amount of mechanical energy of the bob. The other force acting upon |
| + | the bob is the force of tension. Tension is an external force and if |
| + | it did do work upon the pendulum bob it would indeed serve to change |
| + | the total mechanical energy of the bob. However, the force of tension |
| + | does not do work since it always acts in a direction perpendicular to |
| + | the motion of the bob. At all points in the trajectory of the |
| + | pendulum bob, the angle between the force of tension and its |
| + | direction of motion is 90 degrees. Thus, the force of tension does |
| + | not do work upon the bob. |
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| + | Since there are no external forces doing work, the total |
| + | mechanical energy of the pendulum bob is conserved. |
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| =Method= | | =Method= |
| ==Time== | | ==Time== |