Modelling with functions Quiz

1. The model $T=20+70e^{-0.05t}$ describes cooling. What is $T$ when $t=0$?

• A. $70$
• B. $90$
• C. $20$
• D. $50$

2. A tide model is $d=6+2.5\sin(30t)^\circ$. Its maximum depth is

• A. $8.5$ m
• B. $2.5$ m
• C. $6$ m
• D. $3.5$ m

3. $P$ is inversely proportional to $V$, and $P=50$ when $V=4$. Find $P$ when $V=10$.

• A. $125$
• B. $2$
• C. $12.5$
• D. $20$

4. For $N=500e^{0.4t}$, the rate of increase at time $t$ is

• A. $500N$
• B. $e^{0.4t}$
• C. $0.4N$
• D. $0.4t$

5. Which is the best criticism of $N=500e^{0.4t}$ for large $t$?

• A. it predicts a negative population
• B. it predicts unlimited growth
• C. it gives $N=0$ at the start
• D. it has a period