Numerade

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4.2.27. Records show that deaths occur at the rate of 0.1 per day among patients residing in a large nursing home. If someone dies today, what are the chances that a week or more will elapse before another death occurs?

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The rate of killing by an antimicrobial agent may slow when the microbial population has been greatly reduced because the remaining population may have a high proportion of resistant organisms. True or False True False

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When buying a new optical drive for a computer, which of the following factors should you consider?

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Problem 6-10 A rotating shaft of 25-mm diameter is simply supported by bearing reaction forces $R_1$ and $R_2$. The shaft is loaded with a transverse load of 13 kN as shown in the figure. The shaft is made from AISI 1045 machine finished steel whose strengths are $S_{ut} = 570$ MPa and $S_y = 310$ MPa. The surface has been machined. Determine (a) the minimum static factor of safety based on yielding. (b) the endurance limit, adjusted by factors discussed in class. (hint: do not consider temperature and reliability factors because the information about temperature and reliability is not given.) (c) the minimum fatigue factor of safety based on achieving infinite life. (hint: $n_f = \frac{S_e}{\sigma_{max}}$) (d) If the fatigue factor of safety is less than 1 (hint: it should be for this problem), then estimate the life of the part in number of rotations. Ans: $n_y = 0.98$, $S_e = 192$ MPa, $n_f = 0.6$, $N \approx 25000$ cycles Hint: Use Fig. 6-23, $f = 0.87$ If you use Eq. (6-11), $f = 0.875$, and N will be slightly different.

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In metaphase I, how do chromosomes line up? What is independent assortment?

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Determine the equation of the circle with radius √111 and center (9,5).

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Find the best approximation to $z$ by vectors of the form $c_1v_1 + c_2v_2$. $z = \begin{bmatrix} 2 \\ -6 \\ 4 \\ 2 \end{bmatrix}, v_1 = \begin{bmatrix} 4 \\ 1 \\ -2 \\ -1 \end{bmatrix}, v_2 = \begin{bmatrix} 1 \\ -2 \\ 0 \\ 2 \end{bmatrix}$ The best approximation to $z$ is $\boxed{\qquad}$ (Simplify your answer.)

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1) For each statistical mechanics ensemble (microcanonical, canonical, grandcanonical) prove the following formula for the entropy: $S = -k_B \sum P_j \ln(P_j)$ where $P_j$ is the probability of microstate j.

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*2.12. The input to the translational mechanical system shown in Figure P2.12 is the displacement $x_3(t)$ of the right end of the spring $K_1$. The displacement of $M_2$ relative to $M_1$ is $x_2$. The forces exerted by the springs are zero when $x_1 = x_2 = x_3 = 0$. Draw the free-body diagrams and write the modeling equations.

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Name: solution Given the following matrix equations and i?(t) = 10sin(377t) amps and i?(t) = 10cos(377t) amps, determine the matrix inverse, prove it is the inverse, solve for V? and V?, and finally determine v?(t) and v?(t). $\begin{bmatrix} 1 & j0.5 \ 0 & 0.5 \end{bmatrix} \begin{bmatrix} V_1 \ V_2 \end{bmatrix} = \begin{bmatrix} I_1 \ I_2 \end{bmatrix}$

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james a.