Give the oxidation numbers for the following species:

$$\mathrm{H_2,\;Se_8,\;P_4,\;O,\;U,\;As_4,\;B_{12}.}$$

A yard that is to be covered with mats of grass is shaped like a trapezoid. The bases are $80$ feet and $100$ feet, and the height is $60$ feet. What is the cost of putting the grass mats on the yard if the landscaper charges $\$ 0.35$ per square foot?

Suppose a horizontal force of 20 N is required to maintain a speed of 8 m/s of a 50 kg crate. (a) What is the power of this force? (b) Note that the acceleration of the crate is zero despite the fact that 20 N force acts on the crate horizontally. What happens to that energy given to the crate as a result of the work done by this 20 N force?

A discount pass for a bridge costs $30 per month. The toll for the bridge is normally$5.00, but it is reduced to $3.50 for people who have purchased the discount pass. Determine the number of times in a month the bridge must be crossed so that the total monthly cost without the discount pass is the same as the total monthly cost with the discount pass.

Since the force that acts on a cannonball when a cannon is fired is equal and equal to the force that acts on the cannon, does this imply a zero net force and therefore the impossibility of an accelerating cannonball? Explain.

On January 2, 2006, Hagen Corporation purchased equipment costing $72,000. Hagen performs adjusting entries monthly.
a. Record this equipment's depreciation expense on December 31, 2011, assuming its estimated life was eight years on January 2, 2006.

Johnson Company sold for $90,000 a$102,400, 2-year zero coupon bond on January 1, 2020. The bond matures on December 31, 2021.

Required:

Prepare the entry to recognize the 2021 interest expense and the repayment of the bond on December 31, 2021.

Find the list price, given the net cost and the series discount.

Net cost $518.40; trade discount 20/10

DNA compression. Due to its double-helix structure, a DNA molecule acts like a spring that can be compressed. Biophysicists have estimated the force constant for one type of DNA molecule to be $0.60 \mathrm{nN} / \mathrm{nm}$. Find the compression of a $75-\mu \mathrm{m}$-long DNA molecule that acquires a charge of $+1.2 \mathrm{pC}$ at one end and $-1.2 \mathrm{pC}$ at the other.

At the end of each fiscal period, Kimura Corporation prepares adjusting entries to record accrued interest expense. However, the company does not record reversing entries for the accrued interest expense. At the end of the current fiscal year, Kimura had a $3,000.00, 90-day, 10% note payable outstanding, signed November 1. Kimura made the following journal entries related to the note. $$ \begin{matrix}\mathrm{\scriptscriptstyle Signed \ Note \ Nov. \ 1} & & \mathrm{\scriptscriptstyle Closing \ Entry \ Dec. \ 31}\\\mathrm{\scriptscriptstyle Cash} & \mathrm{\scriptscriptstyle $3,000.00} & \mathrm{\scriptscriptstyle Income \ Summary} & \mathrm{\scriptscriptstyle 50.00}\\\mathrm{\scriptscriptstyle Notes \ Payable} & \mathrm{\scriptscriptstyle $3,000.00} & \mathrm{\scriptscriptstyle Interest \ Expense} & \mathrm{\scriptscriptstyle 50.00}\\\mathrm{\scriptscriptstyle Adj. \ Entry \ Dec. \ 31} & & \mathrm{\scriptscriptstyle Paid \ Note \ Jan. \ 30}\\\mathrm{\scriptscriptstyle Interest \ Expense} & \mathrm{\scriptscriptstyle 50.00} & \mathrm{\scriptscriptstyle Notes \ Payable} & \mathrm{\scriptscriptstyle 3,000.00}\\\mathrm{\scriptscriptstyle Interest \ Payable} & \mathrm{\scriptscriptstyle 50.00} & \mathrm{\scriptscriptstyle Interest \ Payable} & \mathrm{\scriptscriptstyle 50.00}\\ & & \mathrm{\scriptscriptstyle Interest \ Expense} & \mathrm{\scriptscriptstyle 25.00}\\ & & \mathrm{\scriptscriptstyle Cash} & \mathrm{\scriptscriptstyle 3,075.00}\\\end{matrix} $$ Isabel Lugo, an accounting supervisor, says that generally accepted accounting principles require that reversing entries be used in conjunction with adjusting entries for accrued expenses. Thus, Ms. Lugo says Kimura must begin using reversing entries for all accrued expenses. Is she correct? Do the procedures Kimura has been using result in incorrect financial statements? Explain.

Give the oxidation number for the underlined atom in the following molecule: $\mathrm{Ca}\underline{\mathrm{C}}_2$

An air conditioner connected to a 120 V rms ac line is equivalent to a 12.0 $\Omega$ resistance and a 1.30 $\Omega$ inductive reactance in series. Calculate the average rate at which energy is supplied to the appliance.

Tell whether the reasoning process is deductive or inductive.

Linda observes that $(-1)^2=+1,(-1)^4=+1$, and $(-1)^6=+1$. She concludes that every even power of $(-1)$ is equal to $+1$.

A gymnast is bouncing on a trampoline. After a high bounce the gymnast comes down and hits the elastic surface of the trampoline. In so doing the gymnast applies a force to the trampoline. (a) Describe the effect this force has on the elastic surface. (b) The surface applies a reaction force to the gymnast. Describe the effect that this reaction force has on the gymnast.