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.

When Earth traveled through the storm of meteorites trailing the comet Tempel-Tuttle on November 17, 1998, the storm was 1,000 times as intense as the average meteor storm. Before the comet arrived, telecommunication companies worried about the potential damage that might be inflicted on the approximately 650 satellites in orbit. It was estimated that each satellite had a 1% chance of being hit, causing damage to the satellite’s electronic system. One company had five satellites in orbit at the time. Determine the probability distribution of the number of the company’s satellites that would be damaged.

A typical tractor-trailer will move $18$ tons of air per mile at $55 \mathrm{~mph}$. Air resistance increases with speed, causing fuel efficiency to decrease at higher speeds. At highway speeds, a certain truck's fuel efficiency $t$, in miles per gallon ($\mathrm{mpg}$), can be approximated by

$$t=-0.1 s+13.1,$$

where $s$ is the speed of the truck, in miles per hour ($\mathrm{mph}$). Graph the equation and then use the graph to estimate the fuel efficiency at $66 \mathrm{~mph}$.

Doctors Mowtain, Lawrence, and Curley are radiologists living in Yukville, Maine. They realize that many of the state's small, rural hospitals cannot afford to purchase their own magnetic resonance imaging devices (MRIs). The doctors are considering whether it would be feasible for them to form a corporation and invest in their own MRI unit. The unit would be transported on a scheduled basis to more than 80 rural hospitals using an 18-wheel tractor-trailer. The cost of a tractor-trailer equipped with MRI equipment is approximately $\$ 1,500,000$. The estimated life of the investment is nine years, after which time its salvage value is expected to be no more than $\$ 200,000$.

The doctors anticipate that the investment will generate incremental revenue of $\$ 900,000$ per year. Incremental expenses (which include depreciation, insurance, fuel, maintenance, their salaries, and income taxes) will average $\$ 800,000$ per year. Net incremental cash flows will be reinvested back into the corporation. The only difference between incremental cash flows and incremental income is attributable to depreciation expense. The doctors require a minimum return on their investment of 15 percent.

What nonfinancial factors should the doctors consider in making this decision?

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?

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.

Consider the following hypothesis test:

$$\begin{array} { l } { H _ { 0 } : \mu = 18 } \\ { H _ { \mathrm { a } } : \mu \neq 18 } \end{array}$$

A sample of 48 provided a sample mean $\overline { x } = 17$ and a sample standard deviation $s = 4.5$.

Compute the value of the test statistic.

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?

Doctors Hanson, Dominick, and Borchard are radiologists living in Fargo, North Dakota. They realize that many of the state's small, rural hospitals cannot afford to purchase their own magnetic resonance imaging devices (MRIs). Thus, the doctors are considering whether it would be feasible for them to form a corporation and invest in their own mobile MRI unit. The unit would be transported on a scheduled basis to more than 100 rural hospitals using an 18-wheel tractor-trailer. The cost of a tractor-trailer equipped with MRI equipment is approximately $\$ 1,250,000$. The estimated life of the investment is eight years, after which time its salvage value is expected to be no more than $\$ 100,000$. The doctors anticipate that the investment will generate incremental revenue of $\$ 800,000$ per year. Incremental expenses (which include depreciation, insurance, fuel, maintenance, their salaries, and income taxes) will average $\$ 700,000$ per year. Net incremental cash flows will be reinvested back into the corporation. The only difference between incremental cash flows and incremental income is attributable to depreciation expense. The doctors require a minimum return on their investment of 12 percent.

Compute the payback period of the mobile MRI proposal.

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 accelerating a $2000-\mathrm{kg}$ trailer to $60 \mathrm{m/sec}$ in 20 sec. Assume a constant acceleration. (also see the given 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.

Consider the following hypothesis test:

$$\begin{array} { l } { H _ { 0 } : \mu \leq 12 } \\ { H _ { \mathrm { a } } : \mu > 12 } \end{array}$$

A sample of 25 provided a sample mean $\overline { x } = 14$ and a sample standard deviation $s = 4.32$.

Compute the value of the test statistic.

Andy Tedesco is interested in buying a small pickup with a base price of $31,100. It has these options: stereo/CD player /navigation system,$1,445; power sunroof, $850; security package,$640; aluminum wheels, $545; tubular side steps,$525; heated front seats, $250; trailer tow group,$525; pearl coat paint, $225; and all-terrain tires,$100. Its destination charge is $645. Determine its sticker price.

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.

A food trailer serves chicken and records the order size and sides on their orders, as shown in the table.

Green Salad: 2 pieces 33 and 3 pieces 13 Macaroni & Cheese: 2 pieces 22 and 3 pieces 55 French Fries: 2 pieces 52 and 3 pieces 65 Cole Slaw: 2 pieces 35 and 3 pieces 55

Explain how to find the experimental probability that the next order is two pieces of chicken with a green salad.