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 sheet’s thickness (in meters) after t weeks. s = -0.25t + 4 what is the ice sheet’s thickness at the beginning of spring? meters

Explanation:

Step1: Identify the time at the beginning of spring

At the beginning of spring, the number of weeks \( t \) since the start of melting is \( 0 \) (because melting just starts).

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

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

Step3: Calculate the value of \( S \)

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

Answer:

4