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ANSWERED

Nicole Smina verified

Numerade educator

(a) a shiny piece of iron metal gets rusty when left outside; (b) the purple crystalline solid potassium permanganate forms a purple solution when dissolved in water; (c) the shiny metal mercury is a liquid at room temperature.

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Paul Gabriel verified

Numerade educator

A player bounces a $0.43-\mathrm{kg}$ soccer ball off head, changing the velocity of the ball from $\overrightarrow{\mathbf{v}}_{1}=(8.8 \mathrm{m} / \mathrm{s}) \hat{\mathbf{x}}+(-2.3 \mathrm{m} / \mathrm{s}) \hat{\mathbf{y}}$ to $\overrightarrow{\mathbf{v}}_{\mathrm{f}}=(5.2 \mathrm{m} / \mathrm{s}) \hat{\mathbf{x}}+(3.7 \mathrm{m} / \mathrm{s}) \hat{\mathbf{y}} .$ If the ball is in contact with the player's head for 6.7 $\mathrm{ms}$ , what are (a) the direction and (b) the magnitude of the impulse delivered to the ball?

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ANSWERED

Paul Gabriel verified

Numerade educator

(II) You buy an "airtight" bag of potato chips packaged at sea level, and take the chips on an airplane flight. When you take the potato chips out of your "carry-on" bag, you notice it has noticeably "puffed up." Airplane cabins are typically pressurized at 0.75 atm, and assuming the temperature inside an airplane is about the same as inside a potato chip processing plant, by what percentage has the bag "puffed up" in comparison to when it was packaged?

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For each of the following exercises, find the distance between the two points. Simplify your answers, and write the exact answer in simplest radical form for irrational answers. $$(-4,3)\text { and }(10,3)$$

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ANSWERED

David Collins verified

Numerade educator

The half-life of cobalt--60 is 10.47 min. How many milligrams of $\mathrm{Co}-60$ remain after 104.7 min if you start with 10.0 $\mathrm{mg}$ of $\mathrm{Co}-60$ ?

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Darshan Maheshwari verified

Numerade educator

A car starts from the origin and is driven $1.2 \mathrm{km}$ south and then $3.1 \mathrm{km}$ in a direction $53^{\circ}$ north of east. Relative to the origin, what is the car's final location? Express your answer in terms of a distance and an angle.

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INSTANT ANSWER

A particle traveling in a straight line is located at the point $(1,-1,2)$ and has speed 2 at time $t=0$ . The particle moves toward the point $(3,0,3)$ with constant acceleration $2 \mathbf{i}+\mathbf{j}+\mathbf{k}$ . Find its position vector $\mathbf{r}(t)$ at time $t .$

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INSTANT ANSWER

General Zod has sold Lex Luthor what Zod claims to be a new copper-colored form of kryptonite, the only substance that can harm Superman. Lex, not believing in honor among thieves, decided to carry out some tests on the supposed kryptonite. From previous tests, Lex knew that kryptonite is a metal having a specific heat capacity of 0.082 $\mathrm{J} / \mathrm{g} \cdot^{\circ} \mathrm{C}$ and a density of 9.2 $\mathrm{g} / \mathrm{cm}^{3}$ Lex Luthor's first experiment was an attempt to find the specific heat capacity of kryptonite. He dropped a $10 \mathrm{g} \pm 3 \mathrm{g}$ sample of the metal into a boiling water bath at a temperature of $100.0^{\circ} \mathrm{C} \pm 0.2^{\circ} \mathrm{C}$ . He waited until the metal had reached the bath temperature and then quickly transferred it to $100 \mathrm{g} \pm$ 3 $\mathrm{g}$ of water that was contained in a calorimeter at an initial temperature of $25.0^{\circ} \mathrm{C} \pm 0.2^{\circ} \mathrm{C}$ . The final temperature of the metal and water was $25.2^{\circ} \mathrm{C} .$ Based on these results, is it possible to distinguish between copper and kryptonite? Explain. When Lex found that his results from the first experiment were inconclusive, he decided to determine the density of the sample. He managed to steal a better balance and determined the mass of another portion of the purported kryptonite to be $4 \mathrm{g} \pm 1 \mathrm{g} .$ He dropped this sample into water contained in a $25-\mathrm{mL}$ graduated cylinder and found that it displaced a volume of $0.42 \mathrm{mL} \pm 0.02 \mathrm{mL}$ . Is the metal copper or kryptonite? Explain. Lex was finally forced to determine the crystal structure of the metal General Zod had given him. He found that the cubic unit cell contained four atoms and had an edge length of $600 . \mathrm{pm}$ . Explain how this information enabled Lex to identify the metal as copper or kryptonite. Will Lex be going after Superman with the kryptonite or seeking revenge on General Zod? What improvements could he have made in his experimental techniques to avoid performing the crystal structure determination?

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ANSWERED

Eduard Sanchez verified

Numerade educator

(II) A sphere of radius $r = 34.5 cm$ and mass $m = 1.80 kg$ starts from rest and rolls without slipping down a 30.0$^{\circ}$ incline that is 10.0 m long. $(a)$ Calculate its translational and rotational speeds when it reaches the bottom. $(b)$ What is the ratio of translational to rotational kinetic energy at the bottom? Avoid putting in numbers until the end so you can answer: $(c)$ do your answers in $(a)$ and $(b)$ depend on the radius of the sphere or its mass?

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INSTANT ANSWER

A, B, and C are three aldohexoses. Compounds A and B yield the same optically active alditol when they are reduced with hydrogen and a caralyst; A and B yield different phenylosazones when treated with phenylhydrazine; B and C give the same phenylosazone but different alditols. Assuming that all are $\mathrm{D}$ sugars, give names and structures for $\mathbf{A}, \mathbf{B},$ and $\mathbf{C}$.0

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