Final answer:
Pyroclastic flows can move at speeds of up to 700 km/h or around 200 m/s, which makes D) 200 m/sec the correct answer for the speed at which they can travel.
Step-by-step explanation:
Pyroclastic flows are fast-moving currents of hot gas and volcanic matter (collectively known as tephra) that move away from a volcano at high speeds. They are considered to be some of the most dangerous phenomena associated with volcanic eruptions due to their speed, high temperature, and ability to travel long distances over land and water.
Pyroclastic flows can move at speeds of up to 700 km/h (approximately 200 m/s), which is much faster than the average human can run. They are capable of covering vast distances very quickly, and because of their high temperature and the debris they carry, they can completely destroy nearly everything in their path.
Given the options in the question:
- A) 10 m/sec
- B) 50 m/sec
- C) 100 m/sec
- D) 200 m/sec
The correct answer for the speed of pyroclastic flows is D) 200 m/sec, as they can travel at speeds far exceeding the other options provided.