Daily Science (pg. 52)

1. Name an example of a transverse wave and a longitudinal wave.

2. Put these numbers into scientific notation:1. 0.00000003472. 405000000003. 0.00000124. 109000000000000000000

3. Divide the following numbers1. 3.0 x 108 / 6.7 x 10-12

2. 9.54 x 1037/ 1.07 x 1013

3. 6.7 x 10-14 / 8.1 x 10-6

Sound

Pg. 53

Properties of sound Sound waves- longitudinal waves that are caused by

vibrations and travels through a medium Speed of sound-depends on the material and the

temperature through which it travels Loudness-determined by intensity Intensity-the rate at which a sound wave transmits

energy (depends on amplitude and distance from source).

Intensity Measured in decibels (dB) Threshold of hearing: quietest sound a human can

hear (0 dB) Threshold of pain: sounds louder can cause

deafness (120 dB). Ex. 30 dB- cat purring

50 dB- normal conversation 90 dB- lawn mower 150 dB- nearby jet airplane

Sound characteristics

Pitch-measure of how high or low something sounds Higher frequency higher pitch Any sound that has a frequency below human

hearing is called infrasound. Any sound with a frequency above human hearing is

called ultrasound.

Musical instruments Rely on standing waves The player controls the vibrations of the standing

waves Instruments use resonance to amplify sound. Resonance-a phenomenon that occurs when two

objects vibrate at the same frequency.

The Ear

The ear senses vibrations, amplifies them, and transmits them to the brain.

There are 3 regions: outer ear, middle ear, inner ear.

Ultrasound and Sonar

Reflected waves are used to determine distances and to create images.

Reflected waves from an ultrasound are put into a computer image called a sonogram.

Sonar uses reflected waves to determine distance under water (calculates using the velocity equation).

Bats use ultrasound to fly and locate food.

Pg. 541. Use page 549 in the book to help you label the

parts of an ear. Describe IN YOUR OWN WORDS how sound travels through the ear.

2. Read the article on the corner of my desk. On pg. 54 summarize the article using 5 vocabulary words we have talked about. Include a paragraph on whether or not you think the experiment the scientists was ethical. Provide an example of something they could have done differently.