Question

a lake near the arctic circle is covered by sheet of ice during the cold winter months. when spring arrives, the ice starts to melt.

s models the ice sheets thickness (in meters) after t weeks.

s = -0.25t + 4
what is the ice sheets thickness at the beginning of spring?

○ 4 meters
○ 0.25 meters
○ -0.25 meters
○ 3.75 meters

Explanation:

Step1: Understand the problem

We need to find the ice sheet's thickness at the beginning of spring. At the beginning of spring, the number of weeks \( t \) is 0 because no time has passed yet.

Step2: Substitute \( t = 0 \) into the equation

The equation for the ice sheet's thickness is \( S=- 0.25t + 4 \). Substitute \( t = 0 \) into this equation:
\( S=-0.25\times0 + 4 \)

Step3: Calculate the value of \( S \)

First, calculate \( - 0.25\times0=0 \). Then, \( S = 0 + 4=4 \).

Answer:

4 meters