Question

a tuning fork is vibrating the air around it. what best describes the waves produced by the tuning fork?
mechanical, because the
air molecules are moving
perpendicular to the tuning
fork
electromagnetic, because
the vibrating tuning fork
does not need air in order
to produce sound
electromagnetic, because
the air molecules are
moving parallel to the
tuning fork
mechanical, because the
vibrating tuning fork makes
air molecules around it
vibrate

Explanation:

1. Recall the difference between mechanical and electromagnetic waves: Mechanical waves require a medium (like air, water, solids) to travel, while electromagnetic waves (e.g., light, radio waves) do not and can travel through a vacuum. Sound waves are mechanical waves.
2. Analyze each option:

• First option: Sound waves from a tuning fork are longitudinal (air molecules move parallel to the wave direction), not perpendicular. So this is incorrect.
• Second option: Tuning fork produces sound (mechanical wave), which needs a medium (air). Electromagnetic waves don't need a medium, so this is wrong.
• Third option: Sound is mechanical, not electromagnetic, and air molecules move parallel (longitudinal), but the wave type classification is wrong here.
• Fourth option: Sound waves are mechanical because they need a medium (air), and the vibrating tuning fork causes air molecules to vibrate (transferring energy through the medium), which matches the definition of mechanical waves.

Answer:

The correct option is the fourth one: "mechanical, because the vibrating tuning fork makes air molecules around it vibrate" (assuming the fourth option's full text is as described, with the correct reasoning about mechanical waves needing a medium and the tuning fork causing air molecules to vibrate).