Grade 7 (Physics)

1. By: JENNY P. LAGUNA
Science Teacher

2. are forms of
energy…it consists of a
waves

3. How do sound propagate or spread?
It propagate through a….
…..Solids, Liquids, and Gases…
are…..metals, woods, plastics,
glasses
are….. water (fresh or salt),
milk, mercury, oil, alcohol
are…. Air, oxygen, carbon
dioxide, helium, hydrogen

4. …..need a
medium to propagate.
… travels
parallel to the motion of particles.

6. • Sound travels through a medium,
• There are alternating regions,
– Compressions are high pressure regions where
the molecules are crowded together.
– Rarefactions are low pressure regions where
the molecules are more spread out.

7. • Sound travels through a medium,
• In solids, sound travels fastest-
the molecules are very close to
each other.
• In liquids, sound travels faster
than gas because the molecules
are close to each other.
• In gases, sound travels slowest
because the molecules are far