Numerade

Questions asked

ANSWERED

Paul Gabriel

Numerade educator

Suppose a chinook salmon needs to jump a waterfall that is 1.50 $\mathrm{m}$ high. If the fish starts from a distance 1.00 $\mathrm{m}$ from the base of the ledge over which the waterfall flows, (a) find the $x$ - and $y$ -components of the initial velocity the salmon would need to just reach the ledge at the top of its trajectory. (b) Can the fish make this jump? (Note that a chinook salmon can jump out of the water with an initial speed of 6.26 $\mathrm{m} / \mathrm{s} .$ )

View Answer

ANSWERED

David Mccaslin

Numerade educator

The vitamin content per ounce for three foods is given in the following table. a. Use matrices to show that no combination of these foods can provide exactly 14 mg of thiamin, 32 mg of riboflavin, and 9 mg of niacin. b. Use matrices to describe in practical terms what happens if the riboflavin requirement is increased by 5 mg and the other requirements stay the same.

View Answer

ANSWERED

Nicole Smina

Numerade educator

Each of the following IUPAC names is incorrect. Explain why it is incorrect and give the correct IUPAC name. a. 2,2-dimethyl-4-ethylheptane b. 5-ethyl-2-methylhexane c. 2-methyl-2-isopropylheptane d. 1,5-dimethylcyclohexane e. 1-ethyl-2,6-dimethylcycloheptane f. 5,5,6-trimethyloctane g. 3-butyl-2,2-dimethylhexane h. 1,3-dimethylbutane

View Answer

ANSWERED

Lunar eclipses are always eclipses of a full Moon. That is, the Moon is always seen full just before and after Earth's shadow passes over it. Why is this? Why can't we ever have a lunar eclipse when the Moon is in its crescent or half-moon phase?

View Answer

ANSWERED

Eduard Sanchez

Numerade educator

A 0.12 kg body undergoes simple harmonic motion of amplitude 8.5 $\mathrm{cm}$ and period 0.20 $\mathrm{s}$ (a) What is the magnitude of the maximum force acting on it? (b) If the oscillations are produced by a spring, what is the spring constant?

View Answer

INSTANT ANSWER

How many pivot columns must a $7 \times 5$ matrix have if its columns are linearly independent? Why?

View Answer

INSTANT ANSWER

Use a rectangular coordinate system to plot $\mathbf{u}=\left[\begin{array}{l}{5} \\ {2}\end{array}\right], \mathbf{v}=\left[\begin{array}{r}{-2} \\ {4}\end{array}\right],$ and their images under the given transformation $T .$ (Make a separate and reasonably large sketch) Describe geometrically what $T$ does to each vector $\mathbf{x}$ in $\mathbb{R}^{2}$. $T(\mathbf{x})=\left[\begin{array}{rr}{-1} & {0} \\ {0} & {-1}\end{array}\right]\left[\begin{array}{l}{x_{1}} \\ {x_{2}}\end{array}\right]$

View Answer

ANSWERED

Christopher Dzorkpata

Numerade educator

Can two objects have the same inertia but a different moment of inertia?

View Answer

ANSWERED

Chandan Gupta

Numerade educator

For a new car the number of defects $X$ has the distribution given by the accompanying table Find $M_{X}(t)$ and use it to find $E(X)$ and $\operatorname{SD}(X)$ . $$\begin{array}{ccccccc}{x} & {0} & {1} & {2} & {3} & {4} & {5} & {6} \\ \hline p(x) & {.04} & {.20} & {.34} & {.20} & {.15} & {.04} & {.03}\end{array}$$

View Answer

INSTANT ANSWER

For a camera with a lens of fixed focal length $F$ to focus on an object located a distance $x$ from the lens, the film must be placed a distance $y$ behind the lens, where $F, x,$ and $y$ are related by $$\frac{1}{x}+\frac{1}{y}=\frac{1}{F}$$ (See the figure.) Suppose the camera has a $55-\mathrm{mm}$ lens $(F=55) .$ (a) Express $y$ as a function of $x$ and graph the function. (b) Express happens to the focusing distance $y$ as the object moves far away from the lens? (c) What happens to the focusing distance $y$ as the object moves close to the lens?

View Answer

Patrick T.