Question

this graph is accurate because... a mechanical waves move faster than electromagnetic waves. b electromagnetic waves cannot travel through a vacuum. c mechanical waves cannot travel through a medium. d electromagnetic waves move faster than mechanical waves.

Explanation:

Electromagnetic waves travel at the speed of light in a vacuum ($3\times10^{8}$ m/s), while mechanical waves require a medium to travel and generally have much lower speeds. For example, sound (a mechanical - wave) travels at about 343 m/s in air at room temperature.

Answer:

D. electromagnetic waves move faster than mechanical waves.