Answer the questions below.

Question

Note that a change can be an increase or a decrease.For an increase, use a positive number.For a decrease, use a negative number.
(a)A tram moved upward
5
meters per second for
45
seconds. What was the total change in the tram's elevation?
225meters
(b)In a lab, a substance was cooled by
48°C
over a period of
8
hours at a constant rate. What was the change in temperature each hour?
6°C

Answer 1

(a) To calculate the total change in the tram's elevation, you multiply the speed by the time:

\[ 5 , \text{meters/second} \times 45 , \text{seconds} = 225 , \text{meters} \]

So, the total change in the tram's elevation is 225 meters.

(b) To calculate the change in temperature each hour, you divide the total change in temperature by the number of hours:

\[ \frac{-48 , \text{°C}}{8 , \text{hours}} = -6 , \text{°C/hour} \]

Thus, the change in temperature each hour is -6°C. (The negative sign indicates a decrease.)