. A vertical line segment of length 8 ft is moving horizontally at a rate of 3 ft/sec. At what rate is area being swept out by the moving vertical segment?

1. A vertical line segment of length 8 ft is moving horizontally at a rate of 3 ft/sec. At what rate is area
being swept out by the moving vertical segment? 

Consider the area formed by the line f(x) = mx, the x axis, and the vertical segment at location x.
The vertical segment is moving to the right at 3 ft/sec. At a certain time, say t = T, the height of the
vertical segment is 8 ft. 

 At t = T is the area of the triangle increasing at a rate equal to, or greater than, the rate area is
swept by the segment in Problem 1? (Ok to guess here). Let A(x) be the area of the triangle. Find the rate at which the area is increasing when t = T.