Write the compound subject or predicate in each sentence below. Underline the subjects once and the verbs twice.

Example: The brain and heart function differently at high altitudes.

Answer: $\underline{\text{{brain}}}$ and $\underline{\text{{heart}}}$

Electrical activity and chemical actions in the brain keep the body alive.

Every cell in the body has organelles called mitochondria that can generate a voltage difference between their interior and exterior. If the capacitance of a mitochondrion is $4.3 \times 10^{-11} \mathrm{~F}$ and the potential difference between the interior and exterior is $0.18 \mathrm{~V}$, how much electrical energy does it store?

Electric guitar strings can be magnetized. The strings lie closely over and perpendicular to a coil ,of wire. Inside the coil are permanent magnets that magnetize the segments of the strings overhead. Using this arrangement, explain how the vibrations of a plucked string produce an electrical signal at the same frequency as .the vibration of the string.

An electrical circuit switches instantaneously from a $6$ volt battery to a $12$ volt battery $7$ seconds after being turned on. Graph the battery voltage against time. Give formulas for the function represented by your graph. What can you say about the continuity of this function?

An electrical circuit switches instantaneously from a 6-volt battery to a 12-volt battery 7 seconds after being turned on. Graph the battery voltage against time. Give formulas for the function represented by your graph. What can you say about the continuity of this function?

The headlights of a moving car require about $10 \mathrm{~A}$ from the $12 \mathrm{~V}$ alternator, which is driven by the engine. Assume the alternator is $85 \%$ efficient (its output electrical power is $85 \%$ of its input mechanical power), and estimate the horsepower the engine must supply to run the lights.

The average wind speed at a proposed HAWT wind farm site is 12.5 m/s. The power coefficient of each wind turbine is predicted to be 0.41, and the combined efficiency of the gearbox and generator is 92 percent. Each wind turbine must produce 2.5 MW of electrical power when the wind blows at 12.5 m/s. (a) Calculate the required diameter of each turbine disk. Take the average air density to be $p = 1.2 kg/m^3.$ (b) If 30 such turbines are built on the site and an average home in the area consumes approximately 1.5 kW of electrical power, estimate how many homes can be powered by this wind farm, assuming an additional efficiency of 96 percent to account for the powerline losses.

Given the oscillating current in an electrical circuit is

$$I=2\sin(60\pi t)+\cos(120\pi t)$$

such that $I$ is measured in amperes and $t$ is measured in seconds. Find the average current for each time interval.

$$0\leq t\leq\frac{1}{240}$$

Sensory receptors respond to an appropriate stim ulus with an electrical signal called a(n) _________. Larger stimuli cause these signals to be larger than the signals from small stimuli. Ultimately, the intensity of a stimulus is conveyed to the brain encoded by the _______of action potentials in axons connected to specific sensory areas of the brain.

A swimming pool filled with water has dimensions of $5.00 \mathrm{m} \times 10.0 \mathrm{m} \times 1.78 \mathrm{m}$. Calculate the cost of heating the pool from $15.5^{\circ} \mathrm{C}$ to $26.5^{\circ} \mathrm{C}$ if electrical energy costs $0.100 per kilowatt-hour.

Kegler Bowling buys scorekeeping equipment with an invoice cost of $190,000. The electrical work required for the installation costs$20,000. Additional costs are $4,000 for delivery and$13,700 for sales tax. During the installation, the equipment was damaged and the cost of repair was $1,850. What is the total recorded cost of the scorekeeping equipment?

A well-insulated, rigid vessel contains 3 kg of saturated liquid water at 40$^\circ{}$C. The vessel also contains an electrical resistor that draws 10 A when 50 V are applied. Determine the final temperature in the vessel after the resistor has been operating for 30 min.

Complex numbers are used in the study of electrical circuits. Impedance $Z$ (or the opposition to the flow of electricity), voltage $V$, and current I can all be represented by complex numbers. They are related by the equation $Z=\frac{V}{T}$. Find the value of the missing variable.

$I=1+2 i\quad$ $Z=3-4 i$

Electrical power $P$ is given by

$$P=\frac{E^2}{R}$$

where $E$ is voltage and $R$ is resistance. Approximate the maximum percent error in calculating power if $200$ volts is applied to a $4000 \mathrm{~ohm}$ resistor and the possible percent errors in measuring $E$ and $R$ are $2 \%$ and $3 \%$, respectively.