20 R [3] A closed cylindrical barrel of radius R and length L, is half full with oil of weight density w and lies on F the ground on the edge AB as shown in Fig. 3. The force F exerted by the oil on the circular side is given by R F = 2wxRxdr. Use the trapezoid rule with five 0 intervals and the term R2.2) of the Romberg algorithm to calculate the force F for R=2 ft and w = 90 lb/ft. A dx 6'- BI 20 [4] Fig. 3. Fluid barrel VRx Write a C++ program that estimates the force exerted by the oil from problem [4]. The main program should request from the user the values of a, b and n (let the user know the units), should call a function named Trapezoid whose pseudocode is presented below, and should print the value of the force and its units. The function f(x) should be defined using a "define" statement or as a separate function. function Trapezoid (integer n, real a, b) integer i real h, sum, x h (b-a)/n pay for i to n - 1 do xatioh sumsum + f(x) end for sumsum h return sum end function Trapezoid