What is the most powerful volcano

History has seen some monstrous eruptions of volcanoes, from Mount Pinatubo's weather-cooling burp to the explosion of Mt. Tambora, one of the tallest peaks in the Indonesian archipelago.

The power of such eruptions is measured using the Volcanic Explosivity Index (VEI) a classification system developed in the 1980 that's somewhat akin to the magnitude scale for earthquakes. The scale goes from 1 to 8, and each succeeding VEI is 10 times greater than the last.

There haven't been any VEI-8 volcanoes in the last 10,000 years, but human history has seen some powerful and devastating eruptions. Because it's extremely difficult for scientists to be able to rank the strength of eruptions in the same VEI category, here we present the 10 most powerful volcanoes within the last 4,000 years (within human records) first in order of strength, then within each category, in chronological order.

The most powerful volcano has been Italy's Vesuvius which has been a menacing figure since an eruption in 79 CE buried the city of Pompeii.

Over the last 17,000 years, the volcano has gone through eight major explosive eruptions that were followed by large pyroclastic flows.

1. (1.2kw)x(15/60hours) = .3kwh --> a

2. (5kw)x(90/60hours)x(8cents/kwh) = $0.60 --> d

3. microwave --> 1200 watts = (1.2kw)x(6/60hours) = .12kwh

coffee-maker --> 900 watts = (.9kw)x(10/60hours) = .15kwh

therefore, it requires more energy for the coffee-maker to do the same amount of work.

so the answer is a.

your spelling is a little off : ]