MATH, HELE, SCIENCE

What limit of dB (decibels) are considered harmful to the ears? NOTE: It has to be exact.

• 40 dB

• 80 dB

• 100 dB

• 50 dB

STUDY OF SOUND:

• acoustics

• biology

• dentistry

• geology

Humans can hear 20 HZ to?

• 2,000 HZ

• 20,000

The bending of sound as it passes through different medium is called the

______________ of sound.

A. refraction B. reflection C. diffraction D. absorption

• A. refraction

• B. reflection

• C. diffraction

• D. absorption

Sound waves are produced by?

• frequency

• vibrations

What is reflected sound called?

Answer explanation

FUN FACT- In a room, (with NO objects at all) you have to stand 17. 2 m so that you can make n echo.

What tool is NOT a clearing tool?

• bolo

• hoe

• axe

• sprinkler

T OR F? Don't use garden gloves.

• true

• false

CLICK ON THE TILLING TOOLS BELOW. (2)

• fork

• watering can

• bolo

• spade

What tool do we use in loosening little plants?

• garden shears

• axe

• trowel

• hoe