Which sentence contains an example of personification?

A. The wind whipped through the trees, their new leaves singing a beautiful song to Samantha.

B. The branches and dead leaves crackled under her feet.

C. She imagined being an explorer in the 1600s, before there were trails and markers to guide the way.

D. Samantha could hardly believe her luck to see a bear on the first day.

A tractor-trailer truck is coasting freely, with no brakes, down an $8^{\circ}$ slope at $1000$-$\mathrm{m}$ standard altitude. Rolling resistance is $120 \mathrm{~N}$ for every $\mathrm{m} / \mathrm{s}$ of speed. Its frontal area is $9 \mathrm{~m}^2$, and the weight is $65\ \mathrm{kN}$. Compute the terminal coasting velocity, in $\mathrm{mi} / \mathrm{h}$, for $(a)$ no deflector and (b) a deflector installed.

A random sample of 502 Vail Resorts' guests were asked to rate their satisfaction on various attributes of their visit on a scale of 1-5 with 1= very unsatisfied and 5= very satisfied. The regression model was Y= overall satisfaction score, $X_1$= lift line wait, $X_2$= amount of ski trail grooming, $X_3$= ski patrol visibility, and $X_4$= friendliness of guest services. (a) Calculate the t statistic for each coefficient to test for $\beta_j=0$. (b) Look up the critical value of Student's t in Appendix D for a two-tailed test at $\alpha=.01$. Which coefficients differ significantly from zero? (c) Use Excel to find a p-value for each coefficient.

$$\begin{array}{lcc} \hline \text { Predictor } & \text { Coefficient } & \text { SE } \\ \hline \text { Intercept } & 2.8931 & 0.3680 \\ \text { LiftWait } & 0.1542 & 0.0440 \\ \text { AmountGroomed } & 0.2495 & 0.0529 \\ \text { SkiPatroMisibility } & 0.0539 & 0.0443 \\ \text { FriendlinessHosts } & -0.1196 & 0.0623 \\ \hline \end{array}$$

The 2-Mg truck is traveling at 15 m/s when the brakes on all its wheels are applied, causing it to skid for a distance of 10 m before coming to rest. Determine the constant horizontal force developed in the coupling C, and the frictional force developed between the tires of the truck and the road during this time. The total mass of the boat and trailer is 1 Mg.

A model airplane has a wing span of 3.1 ft and a chord (leading edge–trailing edge distance) of 5 in. The model flies in air at 60$^{\circ}F$ and atmospheric pressure. The wing can be regarded as a flat plate so far as drag is concerned. (a) At what speed will a turbulent boundary layer start to develop on the wing? (b) What will be the total drag force on the wing just before turbulence appears?

Here are three situations in which consumers might need some protection. A motorist asks for a tow rope 'strong enough for my trailer'. It breaks the first time he tries to use it. Do you think the consumer needs some legal protection in these cases? For each example. identify which part of UK consumer protection laws have broken by the business selling the goods.

The tractor-trailer unit is moving down the incline with a speed of 5 mi/hr when the driver brakes the tractor to a stop in a distance of 4 ft. Estimate the percent increase n in the hitch-force component which is parallel to the incline, compared with the force present at steady speed. The cart and its load combined weigh 500 lb. State any assumptions.

Suppose that you are driving an 18-wheeler tractor-trailer truck along the highway. A car pulls up alongside your truck and then moves ahead very slowly. As it passes, the combined sound of the car and truck engines pulsates louder and softer. The combined sound can be either a sum of the two sinusoids or a product of them.

At what rate is the car's engine rotating?

Fission tracks are trails found in uranium-bearing minerals, left by fragments released during fission events. The article “Yo-yo Tectonics of the Nigde Massif During Wrenching in Central Anatolia” reports that fifteen tracks on one rock specimen had an average track length of $13\mu m$ with a standard deviation of $2 \mu \mathrm{m}.$ Assuming this to be a random sample from an approximately normal population, find a 99% confidence interval for the mean track length for this rock specimen.

A truck is traveling down a road with a 3-percent grade at a speed of $55 \mathrm{mi} / \mathrm{h}$ when the brakes are applied. Knowing the coefficients of friction between the load and the flatbed trailer shown are $\mathrm{m}_s=0.40$ and $\mathrm{m}_k=0.35$, determine the shortest time in which the rig can be brought to a stop if the load is not to shift.

From the trailer hitch from the figure has loads applied as shown in the figure. The tongue weight of $980 \mathrm{~N}$ acts downward and the pull force of $4905 \mathrm{~N}$ acts horizontally. Using the dimensions of the ball bracket in the figure, draw a free-body diagram of the ball bracket and find the tensile and shear loads applied to the two bolts that attach the bracket to the channel in the figure, determine the horizontal force that will result on the ball from an impact between the ball and the tongue of the $2000-\mathrm{kg}$ trailer if the hitch deflects $2.8 \mathrm{~mm}$ dynamically on impact. The tractor weighs $9807 \mathrm{~N}$. The velocity at impact is $0.3 \mathrm{m/sec}$. (also see the figures) determine the contact stresses in the ball and the ball cup (not shown). Assume that the ball is $2-\mathrm{in} \mathrm{~dia}$ and the ill-fitting ball cup that surrounds it has an internal spherical surface $10\%$ larger in diameter than the ball.

An airplane wing of 2 m chord length (leading edge to trailing edge distance) and 11 m span flies at 200 km/hr in air at 30$^{\circ}C$. Assume that the resistance of the wing surfaces is like that of a flat plate. a. What is the friction drag on the wing? b. What power is required to overcome this? c. How much of the chord is laminar? d. What will be the change in drag if a turbulent boundary layer is tripped at the leading edge?

Chipsealing is a common and relatively inexpensive way to pave a road. A layer of hot tar is sprayed onto the existing road surface and then stone chips are spread over the surface. A heavy roller then embeds the chips in the tar. Once the tar cools, most of the stones are trapped. However, some loose stones are scattered over the surface. They eventually will be swept up by a street cleaner, but if cars drive over the road before then, the rear tires on a leading car can launch stones backward toward a trailing car (Fig, 4.42). Assume that the stones are launched at speed $v_0=11.2 \mathrm{~m} / \mathrm{s}(25$ $\mathrm{mi} / \mathrm{h}$ ), matching the speed of the cars. Also assume that stones can leave the tires of the lead car at road level and at any angle and not be stopped by mud flaps or the underside of the car. In terms of car lengths $L_c=4.50 \mathrm{~m}$, what is the least separation $L$ between the cars such that stones will not hit the trailing car?

Four hundred people were selected from each of the four geographic regions (Midwest, Northeast, South. West) of the United States, and they were asked which form of camping they prefer. Pop-up camper/trailer, family-style (tenting with restrooms), rustic (tenting, no restrooms), or none were the options. The following table displays the survey's findings.

$$\begin{array}{lcccr} \hline & \text { Midwest } & \text { Northeast } & \text { South } & \text { West } \\ \hline \text { Camper/trailer } & 132 & 129 & 129 & 135 \\ \text { Family style } & 180 & 175 & 168 & 146 \\ \text { Rustic } & 46 & 50 & 59 & 68 \\ \text { None } & 42 & 46 & 44 & 51 \\ \hline \end{array}$$

Can you conclude that the distributions of preferred camping types are different for at least two of the regions based on the evidence from these samples? Use $\alpha=.01$.