Answer:
2.5 cm
Step-by-step explanation:
The total surface area of a cylinder is the sum of the two base areas and the lateral area.
S = 2πr² +2πrh
Filling in the given information, we have ...
47.5π = 2πr² +14πr
23.75 = r² +7r . . . . . divide by 2π
23.75 +12.25 = r² +7r +12.25 . . . . . . add the square of 7/2 to complete the square
36 = (r +3.5)² . . . . simplify a bit
6 = r +3.5 . . . . . . . take the positive square root
2.5 = r . . . . . . . . . . subtract 3.5
The radius of the base of the cylinder is 2.5 cm.
