1. An object dropped from rest from the top of a building on Plant X falls a distance s(t)= 11t^2 feet in the first t seconds. Find the average speed of the object during the frist 5 seconds of fall.

2. Often sales of a new product rapidly at first and then level off with time. This is the casewith the sales represented by the function S(t)=600-100t^-1, where t represents time in years. Find the rate of change of sales for the following number of years.

a. 4 years

b. 7 years