Module 7—Oscillatory Motion
Watch and Listen
See how mechanical resonance can destroy a building during an earthquake by viewing the streaming video resonance in buildings. Look for the answers in the video for the following two questions.
Module 7: Lesson 3 Assignment
Remember to submit the answers to TR 4 and TR 5 to your teacher as part of your Module 7: Lesson 3 Assignment.
Try This
TR 4. Compared to audible sound, the frequency of earthquake waves are generally ___________.
TR 5. Buildings between 5 and 40 storeys high are typically __________ with earthquake waves.
Read
Read more about how mechanical resonance is taken into account in construction on pages 385 and 386 in “Resonance Effects on Buildings and Bridges” of the textbook.
Module 7: Lesson 3 Assignment
Remember to submit the answer to TR 6 to your teacher as part of your Module 7: Lesson 3 Assignment.
TR 6. Engineers build energy ________ systems into buildings so that an earthquake will not destroy them easily.
Read
Read more about mechanical resonance in clocks on page 387 of your textbook.
Self-Check
SC 4. Complete question 13 of “7.4 Check and Reflect” on page 388 of your textbook.
Self-Check Answers
SC 4.
- Two advantages of a quartz clock are that it is more accurate than a pendulum clock and it never needs to be wound.
- A disadvantage of a quartz clock is that it cannot work without a battery.
Module 7: Lesson 3 Assignment
Remember to submit the answer to TR 7 to your teacher as part of your Module 7: Lesson 3 Assignment.
TR 7. A 25.0-kg child in Red Deer pumps herself on a swing when she kicks upward on the downswing, thus changing the distance from the pivot point to her centre of gravity from 2.40 m to 2.28 m. What is the difference in the resonant frequency of her swing before the kick and afterwards?