# Physics Pendulum Problems

ACTIVITY 1: Copy and paste the example problem and the steps, so that the steps are in the correct order into a new Word document and upload it to Moodle. Example Problem 1: A hypnotist swings her watch from 20.0cm chain in front of a subject’s eyes. What is the period of the swing of the watch. Thus, we see that the pendulum used by the hypnotist has a period of 0.898s.| Before we can use this formula, however, we must ensure all our variables are in the correct units. The length variable in this formula should be in meters, however our length is in centimeters. Converting centimeters to meters we get:.| We know that a watch swinging back and forth on a chain is a form of a pendulum and that the length of that pendulum is 20.0cm. Also, since we are assuming that the hypnotist is on Earth, we know that the acceleration due to gravity is 9.8m/s2.| Now we are ready to plug into the formula and simplify to get our answer:.| Fortunately, there is a formula specifically for finding the period of a pendulum. We will use the original version of this formula, since it is already solved for T:.| We want to find the period at which a watch swings back and forth on the end of a chain.|

Example Problem 2: A spider swings in the breeze from a silk thread with a period of 0.6s. How long is the spider’s strand of silk? To solve this we use the formula for the period of a pendulum. Since we are trying to find the length, we use the version of this formula that is solved for L:.| We can see that the spider at the end of the strand makes one complete swing, back and forth, every 0.6s.| Plugging in and simplifying, we get:|

Thus, we now know, that the length of the spider’s silk is 0.089m.| We want to know how long a strand of spider’s silk is.|

ACTIVITY 2: Write up an explanation, similar to the ones you unscrambled in activity one, to the problem below using the work for the problem shown below. Do this on your own paper....

Please join StudyMode to read the full document