A rectangle initially has width 7 meters and length 10 meters and is expanding so that the area increases at a rate of 8 square meters per hour. If the width increases by 40 centimeters per hour how quickly does the length increase initially

The length of rectangular is increasing at a rate 0.5714 meters per hour.

Step-by-step explanation:

We are given the following in the question:

Initial dimensions of rectangular box:

Length,l = 10 m

Width,w = 7 m

We have to find the rate of increase of length.

Area of rectangle =

Differentiating we get,

Putting values, we get,

Thus, the length of rectangular is increasing at a rate 0.5714 meters per hour.

215.92 dollars is the answer