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### Ways of Measuring Gravity

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# Ways of Measuring Gravity

By | November 2012
Page 1 of 3
Method 1 - The Pendulum
|A simple pendulum is just a piece of string, with a mass suspended at one end, which is allowed to swing freely. The Earth's gravity controls | |how the pendulum swings. | |Equipment needed: | |string (at least 1 metre long) | |mass tied to one end of the string (called a bob) | |something to suspend the pendulum from | |stop watch | |tape measure | |In the diagram on the right, the dotted line shows the rest position of the pendulum, while the solid line shows the pendulum ready to start | |swinging. The length of the string is L, and the bob on the end of the string is shown as a red blob. | |Start by letting the pendulum swing gently (if the string is not taut all the time, you won't get an accurate value for g). The start the stop | |watch going and time how long it takes to do, say, 10 complete swings (a complete swing is from a given position back to the same position, not| |just a half swing). Repeat the experiment several times. Does it matter where you start the pendulum swinging? | |You should find that it doesn't matter and that the pendulum always takes...

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