(a) Name some words that contain the prefix "pro" or "proto" (b) Explain how someone who did not know the meaning of the word "protostar" could derive its meaning by looking at the word itself.

D’Souza Company sold 10,000 units of its product at a price of $80 per unit. Total variable cost is$50 per unit, consisting of $40 in variable production cost and$10 in variable selling and administrative cost. Compute the manufacturing (production) margin for the company under variable costing.

a. An infinitely long sheet of charge of width L lies i n the xy-plane between x = -L/2 and x = L/2. The surface charge density is $\eta$. Derive an expression for the electric field $\vec{E}$ at height z above the centerline of the sheet. b. Verify that your expression has the expected behavior if $z \ll L \text { and if } z \gg L$. c. Draw a graph of field strength E versus z.

SBD Phone Company sells its waterproof phone case for $90 per unit. Fixed costs total$162,000, and variable costs are $36 per unit. Determine the (1) contribution margin per unit and (2) break-even point in units.

E-Com had net income of $130,000 under variable costing. Beginning and ending inventories were 1,200 units and 4,900 units, respectively. Fixed overhead cost was$2.50 per unit for both the beginning and ending inventory. What is net income under absorption costing?

A red card is illuminated by red light. What color will the card appear? What if it’s illuminated by blue light?

What amount (moles) is represented by each of the following samples? 1.50 g of dry ice

Find the logarithmic derivative. $A(t)=2,000 e^{0.052 t}$

Find the average value of the function on the given interval. If an average value is zero, you may be able to decide this from a quick sketch which shows you that the areas above and below the x axis are the same. $\sin x+\sin ^{2} x \text { on }(0,2 \pi)$

Use Fermat’s principle to find the path followed by a light ray if the index of refraction is proportional to the given function. $\sqrt{y}$

The Earth's atmosphere consists primarily of oxygen (21%) and nitrogen (78%). The rms speed of oxygen molecules $\left(\mathrm{O}_{2}\right)$ in the atmosphere at a certain location is 535 m/s (a) What is the temperature of the atmosphere at this location? (b) Would the rms speed of nitrogen molecules $\left(\mathrm{N}_{2}\right)$ at this location be higher, equal to, or lower than 535 m/s? Explain. (c) Determine the rms speed of $\mathrm{N}_{2}$ at his location.

(A) Find the average value of each function over the indicated interval. (B) Use a graphing calculator to graph the function and its average value over the indicated interval in the same viewing window. $f(t)=3 t^{2}-2 t ;[-1,2]$

Most atoms in nature are found bonded together to form compounds instead of existing as individual atoms. Why is this true?

Arrange the atoms and/or ions in the following groups in order of decreasing size. $\mathrm{O}, \mathrm{O}^{-}, \mathrm{O}^{2-}$