The grade $x$ of a hill is a measure of its steepness. For example, if a road rises ten feet for every one hundred feet of horizontal distance, then it has an uphill grade of $x=\frac{10}{100}$, or $10 \%$. The braking (or stopping) distance $D$ for a car traveling at $50 \mathrm{mph}$ on a wet, uphill grade is given by

$$D(x)=\frac{2500}{30(0.3+x)} .$$

(a) Evaluate $D(0.05)$ and interpret the result.

(b) Describe what happens to braking distance as the hill becomes steeper.

(c) Estimate the grade associated with a braking distance of $220$ feet.

Automatic braking systems (ABS) on automobiles prevent the tires from locking by sensing when the tires stop spinning and then reducing the braking force until they begin to spin again. Knowing that $\mu_{\mathrm{s}}>\mu_{\mathrm{k}}>\mu_{\text {rolling }}$, an automobile equipped with ABS will $(A)$ always stop in a shorter distance $(B)$ stop in shorter distance on dry pavement but not on wet pavement $(C)$ stop in about the same distance $(D)$ always stop in a longer distance than an automobile that stops by locking the tires.

A Machine Fantasy Using your notes from the Quickwrite for "All Watched Over by Machines of Loving Grace," write a paragraph about how your life would be different without your favorite machines. Think hair dryer, washing machine, toaster, car, computer, popcorn popper, chain saw, lawn mower, snow blower, water heater, oil furnace, electric lights.

Determine whether the following arguments are inductive or deductive. If an argument is inductive, determine whether it is strong or weak. If it is deductive, determine whether it is valid or invalid. After taking LSD, Alice said she saw a flying saucer land in the shopping center parking lot. Since Alice has a reputation for always telling the truth, we must conclude that a flying saucer really did land there.

In Fig. we saw earlier, $C_1=6.00 \mu \mathrm{F}, C_2=3.00 \mu \mathrm{F}, C_3=$ $4.00 \mu \mathrm{F}$, and $C_4=8.00 \mu \mathrm{F}$. The capacitor network is connected to an applied potential difference $V_{a b}$. After the charges on the capacitors have reached their final values, the voltage across $\mathrm{C}_3$ is $40.0 \mathrm{~V}$. What are (c) the voltage $V_{a b}$ applied to the network?

Rewrite each sentence, adding a participle that modifies the underlined word. Use at least two past participles. Usage Tip: Remember that a participle always modifies a noun or pronoun. Example: Original Miss Hurd was a $\text{\underline{teacher.}}$ Rewritten Miss Hurd was an $\text{\underline{inspiring teacher.}}$

I felt very proud when I opened the newspaper and saw my $\text{\underline{story.}}$

Hairdryers work by blowing heat that is generated by exposed, high-resistance wires. (a) If a woman using a hairdryer comes in direct contact with the $110-\mathrm{V}$ wires, find the current that travels through her if she is dry and has a resistance of $500, 000 \Omega$ . (b) If she is wet, the resistance of her body can drop as low as $100 \Omega$. Calculate the current that passes through her body at this resistance. (Death can result when a current of $0.07$ A flows through a person's body for more than $1 \mathrm{~s}$.)

Compare carefully to the earlier exercise. A state patrol officer saw a car start from rest at a highway on-ramp. She radioed ahead to another officer $30\ \mathrm{mi}$ along the highway. When the car reached the location of the second officer $30 \mathrm{~min}$ later, it was clocked going $60\ \mathrm{mi} / \mathrm{hr}$. Can the patrol officer conclude that the driver exceeded the speed limit?

Most sentences in the following paragraph contain errors in pronoun usage. Identify each error, and then give the correct pronoun form. If a sentence is already correct, write $C$.

EXAMPLE: Sarah and me are on the track team.

• me-I*

The champion coach Pat Connolly recognized the young runner as a great talent when she saw Ashford race at the University of California at Los Angeles in 1976.

The Merricks are at a beach resort in Cannes. Say what each family member is about to do based on his or her likes or dislikes. There is only one possibility for each.

{ faire de la voile } $\quad${ nager } $\quad$ { faire du parachutisme ascensionnel } $\quad$ { faire du scooter des mers } $\quad$ { bronzer }$\quad$ { faire du ski nautique }

Le chien adore sentir lair mais il n'aime pas la vitesse et $\`{e}$tre mouillé (wet).

On the line provided, write a sentence according to each of the following guidelines. In your sentences use a variety of subjects and verbs.

Example 1. Write a sentence in which you divide a word at the end of the line.

$$\underline{\text{At the antiques store we saw a type-}}$$

$$\underline{\text{writer that was probably eighty years old.}}$$

Write a sentence in which you divide an already hyphenated word at the end of a line.

Consider a potential energy step as shown in Fig. we saw earlier with a beam of particles incident from the left. a) Calculate the reflection coefficient for the case where the energy of the incident particles is less than the height of the potential energy step. b) Calculate the reflection coefficient for the case where the energy of the incident particles is greater than the height of the step. c) Plot your results as a function of the incident energy and comment.

As you saw in Section 2.2, it is vital for scientists to be able to interpret graphs and draw useful information from them. The graph shown is similar to the one Dr. Stephan Custer used in his study of well water levels. Each bullet on the graph represents the result of a water level test.

During Study 1 , by how much did the water level decline between the first measurement and the final measurement?

The following sentence contains two personal pronouns in parentheses. Underline the pronoun that correctly completes the sentence. Then, on the line provided, write DO if the pronoun is a direct object, IO if it is an indirect object, or OP if it is an object of a preposition. Example $\underline{\text{IO}}$ 1. Mr. Graves offered Tranh and (I, $\underline{\text{me}}$) endless encouragement and guidance.

______ Norah saw (they, them) at the party for Darlene.