The video explains how sound waves travel faster through solids like train tracks than through air, allowing one to hear an oncoming train sooner. It defines a medium as the substance through which waves travel, with examples like water for ocean and sound waves. Mechanical waves require a medium, unlike electromagnetic waves, which can travel through a vacuum. The video concludes by explaining that sound cannot travel in space due to the lack of a medium, while light, an electromagnetic wave, can.

Why can you hear a train through the tracks before hearing it through the air?

• Sound waves travel faster through air than solids.

• Sound waves travel faster through solids than air.

• Sound waves cannot travel through solids.

• Sound waves travel at the same speed through all mediums.

What is a medium in the context of wave travel?

• A type of wave that travels through space.

• A wave that does not require a substance to travel.

• The speed at which a wave travels.

• The substance through which a wave travels.

Which type of wave requires a medium to travel?

• Electromagnetic waves

• Mechanical waves

• Light waves

• Radio waves

Can sound waves travel through the vacuum of space?

• No, because space is too cold.

• Yes, because they do not need a medium.

• No, because they require a medium to travel.

• Yes, because they are electromagnetic waves.

What type of wave is light from the sun?

• Mechanical wave

• Sound wave

• Electromagnetic wave

• Ocean wave