Which of These Can Travel at the Speed of Light

question 171

Multiple Choice

Which of these can travel at the speed of light in a vacuum?

• A) visible light, radio waves, X-rays, and gamma rays
• B) only visible light; all other electromagnetic waves travel slower than the speed of light.
• C) visible light, atoms, X-rays, and subatomic particles (e.g., electrons)
• D) visible light, infrared radiation, ultraviolet radiation, and subatomic particles (e.g., electrons)

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Definitions:

Grain Surplus

An excess amount of grain production over the demand, leading to stored or wasted grain.

Market Economy

An economic system where decisions regarding investment, production, and distribution are based on supply and demand, and prices of goods and services are determined in a free price system.

Price Floor

A government-set minimum price that can be charged for goods and services, aimed at protecting producers.

Equilibrium Price

The price at which the quantity of goods supplied matches the quantity of goods demanded.