Mini Exam 42 — Timed Mini Exams

Questions in this quiz (10)

1. The speed of sound is modeled by $$V=331.5+0.62T-0.003h,$$ where $$V$$ is the speed of sound in meters per second, $$T$$ is the air temperature in degrees Celsius, and $$h$$ is the altitude in meters. What is the speed of sound when the temperature is $$20^\circ C$$ and the altitude is $$500$$ meters?

   • $$342.4$$
   • $$342.9$$
   • $$343.5$$
   • $$344.9$$

2. A line $$k$$ has equation $$y=(2m-1)x+4,$$ where $$m\neq0$$. Which equation represents a line perpendicular to $$k$$?

   • $$y=-\frac{1}{2m-1}x+3$$
   • $$y=(1-2m)x+3$$
   • $$y=\frac{1}{2m-1}x+3$$
   • $$y=-(2m-1)x+3$$

3. If $$\frac{x^{5/2}}{x^{-1}}=\sqrt{x^a},$$ what is the value of $$a$$?

   • $$3$$
   • $$5$$
   • $$7$$
   • $$9$$

4. The equation $$\frac{3x-12}{6}=\frac{x}{2}+k$$ has infinitely many solutions. What is the value of $$k$$?

   • $$-4$$
   • $$-2$$
   • $$0$$
   • $$2$$

5. For a constant $$c$$ > $$0$$, how many solutions does the equation $$|x-2|+|x+4|=c$$ have when $$c=10$$?

   • One
   • Two
   • Three
   • Infinitely many

6. The table below shows a linear relationship between breathing rate $$b$$ and heart rate $$h$$. According to the model, what heart rate corresponds to a breathing rate of $$30$$ breaths per minute?

   • 114

7. An investment account is modeled by $$A(t)=25,000(1.04)^t,$$ where $$t$$ is the number of years after the present year. What does the number $$25,000$$ represent?

   • The annual increase in value
   • The account value after one year
   • The initial account balance
   • The interest earned each year

8. The graph of $$f(x)=5(2)^x-7$$ intersects the $$y$$-axis at what point?

   • $$(-2,2)$$
   • $$(-7,0)$$
   • $$(-7,2)$$
   • $$(0,-2)$$

9. A city's population was $$80,000$$ in $$2020$$ and decreases by $$8\%$$ each year. Which function models the population $$P$$, $$t$$ years after $$2020$$?

   • $$P(t)=80,000(0.92)^t$$
   • $$P(t)=80,000(1.08)^t$$
   • $$P(t)=73,600(0.92)^t$$
   • $$P(t)=80,000(0.08)^t$$

10. A square has a diagonal of length $$12\sqrt2$$. A circle is inscribed in the square. What is the area of the circle?

    • $$36\pi$$
    • $$72\pi$$
    • $$144\pi$$
    • $$288\pi$$