Answer: The ice sheet's thickness decrease every 6 weeks= 1.5 meters
Explanation:
GIven: At the beginning of spring, the ice starts to melt. The variable sss models the ice sheet's thickness (in meters) t weeks after the beginning of spring.
At t=0,
So, Thickness of ice sheet at the beginning = 4 meters
Now at t= 6, we get
Thickness of ice sheet after 6 weeks = 2.5 meters
Decrease in thickness = 4 meters - 2.5 meters = 1.5 meters
Hence, the ice sheet's thickness decrease every 6 weeks= 1.5 meters