Physics 4/14: Sound & Earthquake Waves

Open Ended

Share what you did this past weekend. What are your goals for this week?

Multiple Choice

What do waves transmit (transfer)?

• energy

• mass

• matter

• medium

Multiple Choice

What kind of wave is pictured?

• transverse

• longitudinal

Labelling

Label parts of the LONGITUDINAL wave

Drag labels to their correct position on the image

Rarefraction

Compression

Wavelength

Sound

• a longitudinal wave

• Needs a medium of particles to disturb

• Need a source to disturb the particles

• the particles compress and move away

Multiple Choice

Sound is a _____ wave

• longitudinal (compression) wave

• Transverse Wave

Layers of the Earth

By analyzing how P- and S-waves travel through the Earth, we've been able to conclude several things about the the composition of the inner-earth.

Multiple Choice

Which are the P-waves?

(click on the image)

• Green

• Purple

• Neither Green or Purple

Locating an Earthquake

A station has a seismograph that records the ground movement.

First a P-wave will move the ground.

Then a S-wave will follow.

The time difference (interval) can be translated into a distance which the earthquake occurred.

Multiple Choice

Which city was closest to the earthquake registered on the seismographs? (click on image to make it big)

• Osaka

• Tokyo

• Hiroshima

Locating an Earthquake

is performed when three different seismograph stations can each determine how far the earthquake originated from them.

Poll

Do you understand the characteristic of a longitudinal wave?

Earthquake-safe building are more flexible at the posts and base than stiff building.

The purpose is to avoid pancake collapse after a major earthquake

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Earthquake Safe Building Design

​Pancake Collapse

Open Ended

What characteristic (s) makes a building considered earthquake-safe?