Reminder: Bellworks were

collected on Friday. Please hand yours in this morning if

you haven’t already! Reggie

graded and entered those that were

turned in Friday.

Pendulums

• A mass (bob) connected to a rod that experiences simple harmonic motion (SHM) as it swings back and forth without friction

• Frequency (f) – cycles/second (Hz)• Period (T) - time for one cycle (sec)

Pendulums

• f = 1/T• T = 2π (L/g) ½

• L- length of cord• g= acceleration due to

gravity (at sea level)

• Does the mass of the bob have an effect on period?

• A pendulum makes 36 vibrations in 50 seconds. What is its period & frequency?

• You are building a grandfather clock and want the tick and tock to be separated by one second. How long do you make the cable?

• Suppose the cable stretches over time. Will the clock run slow or fast?

Bellwork

• What length would you need to change a cord on a pendulum to decrease its period from 1.7 s to 1 s?

• The length of a simple pendulum is 0.66 m, the pendulum bob has a mass of 310 g. It is released at an angle of 12° to the vertical. With what frequency does it oscillate?

• What is the bob’s maximum speed?