Answer:

Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent an inverse variation if it can be expressed in the form
or 
Let
x-----> the speed of the elevator
y----> the weight it carries
so

<em>Find the constant k</em>
For x=10 ft/sec, y=400 lb
substitute

The equation is

Find the speed for y=500 lb
substitute in the equation

