Answer:
a). 2
b). Moderate
c). 73-112 mph
d). F1
Explanation:
A Fujita scale is a scale that is used to determine the rating for the tornado intensities. It is used to measure the intensity of the tornado and provides a rating based on the damages made by the tornado on the human built structures and other vegetations.
The rating is based on the wind sped and the damages caused by the winds. When the damages caused by a tornado is surveyed, it is compared to the lists of Damage Indicators and the Degree of Damage which helps to estimate the range of the speeds of the tornado and an EF scale rating is provided accordingly.
In the context, It is given that the lightweight roof of a three storied building was uplifted. It was a non residential low rise three story building whose roof was uplifted completely but there was no damages made to the walls of the building.
So according to the EF scale, it provided a rating of :
Damage Indicator Number : 2
Degree of Damage : Moderate
Expected Wind Speed : 73-112 miles per hour
EF-scale Rating : F1