answer:Given: - Number of firings per minute, ( n = 69 ) - Capacitance, ( C = 23 ) nF - Charging factor, ( k = 0.632 ) The pacemaker fires every ( t = frac{60}{n} ) seconds, so ( t = frac{60}{69} ) s. The voltage across the capacitor at time ( t ) in a RC circuit is given by: [ V(t) = V_0(1 - e^{-frac{t}{RC}}) ] where ( V_0 ) is the full battery voltage, ( R ) is the resistance, and ( t ) is the time. Since the capacitor is charged to 63.2% of its full voltage, we have: [ 0.632V_0 = V_0(1 - e^{-frac{t}{RC}}) ] Substituting the time, capacitance, and charging factor: [ 0.632 = 1 - e^{-frac{0.86956}{23 times 10^{-9} times R}} ] Solving for ( R ) involves taking the natural logarithm and rearranging terms: [ R = frac{0.0378069 times 10^9}{ln(1 - 0.632)} ] Calculating further: [ R approx 3.782 times 10^7 , Omega ] Therefore, the resistance value in the heart pacemaker circuit is approximately ( 3.782 times 10^7 , Omega ).

answer:begin{array}{l} begin{array}{l} text{Calculate the sum of the matrices and find the element in the first row, first column}: left( begin{array}{c} 5 -3 2 end{array} right)+left( begin{array}{c} -5 7 -1 end{array} right) end{array} hline begin{array}{l} left( begin{array}{c} 5 -3 2 end{array} right)+left( begin{array}{c} -5 7 -1 end{array} right)=left( begin{array}{c} 5+(-5) -3+7 2+(-1) end{array} right): left( begin{array}{c} 5+(-5) -3+7 2+(-1) end{array} right) end{array} begin{array}{l} 5+(-5)=0: left( begin{array}{c} fbox{0} -3+7 2+(-1) end{array} right) end{array} begin{array}{l} text{Therefore, the element in the first row, first column of the sum is:} fbox{0} end{array} end{array}

answer:1. Monopoly: Google is often cited as a monopoly in the search engine industry. With a market share exceeding 90%, it dominates the sector, leaving its nearest competitor with a mere 2% share. 2. Duopoly: The Canadian airline industry is an example of a duopoly. Air Canada and WestJet collectively control the majority of the domestic air travel market, making it difficult for other airlines to gain significant traction. 3. Oligopoly: The Organization of the Petroleum Exporting Countries (OPEC) represents a classic oligopoly case. Comprised of major oil-producing countries, OPEC collectively decides on production levels to influence global oil prices and maximize the collective profits of its members.

answer:The cost of internal common equity (retained earnings) is the rate of return that a company could earn by investing in its own projects. It is calculated using the Dividend Growth Model, which is: Cost of retained earnings = Expected dividend / Price + Growth rate In this case, the expected dividend is 5.00 per share, the price is 60 per share, and the growth rate is 8%. Therefore, the cost of retained earnings is: Cost of retained earnings = 5 / 60 + 0.08 Cost of retained earnings = 16.33% Since there are no flotation costs associated with retained earnings, the cost of internal common equity is simply the expected return on the company's stock. The cost of internal common equity (retained earnings) is 16.33%.