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Two men with weights in the ratio 4:3 ru...

Two men with weights in the ratio 4:3 run up a staircase in time in the ratio 12:11. The ratio of power of the first to that of second is

A

`4/3`

B

`12/11`

C

`48/33`

D

`11/9`

Text Solution

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The correct Answer is:
To find the ratio of power of the first man to that of the second man, we can follow these steps: ### Step 1: Understand the formula for power Power is defined as the work done per unit time. Mathematically, it is expressed as: \[ P = \frac{W}{t} \] where \( P \) is power, \( W \) is work done, and \( t \) is time taken. ### Step 2: Define the work done by each man The work done by each man to run up the staircase can be expressed as: \[ W = mgh \] where \( m \) is the mass (or weight) of the man, \( g \) is the acceleration due to gravity, and \( h \) is the height of the staircase. Since both men run up the same staircase, the height \( h \) is the same for both. ### Step 3: Set up the ratios Let the weights of the two men be \( W_1 \) and \( W_2 \). According to the problem, the weights are in the ratio: \[ \frac{W_1}{W_2} = \frac{4}{3} \] Let the times taken by the two men to run up the staircase be \( t_1 \) and \( t_2 \). The times are in the ratio: \[ \frac{t_1}{t_2} = \frac{12}{11} \] ### Step 4: Write the expressions for power The power for each man can be expressed as: \[ P_1 = \frac{W_1}{t_1} \] \[ P_2 = \frac{W_2}{t_2} \] ### Step 5: Find the ratio of powers To find the ratio of the powers \( \frac{P_1}{P_2} \): \[ \frac{P_1}{P_2} = \frac{W_1/t_1}{W_2/t_2} = \frac{W_1}{W_2} \cdot \frac{t_2}{t_1} \] ### Step 6: Substitute the known ratios Substituting the ratios we have: \[ \frac{P_1}{P_2} = \left(\frac{4}{3}\right) \cdot \left(\frac{11}{12}\right) \] ### Step 7: Simplify the expression Now, we can simplify this: \[ \frac{P_1}{P_2} = \frac{4 \times 11}{3 \times 12} = \frac{44}{36} = \frac{11}{9} \] ### Conclusion Thus, the ratio of power of the first man to that of the second man is: \[ \frac{P_1}{P_2} = \frac{11}{9} \] ### Final Answer The ratio of power of the first man to that of the second man is \( \frac{11}{9} \). ---

To find the ratio of power of the first man to that of the second man, we can follow these steps: ### Step 1: Understand the formula for power Power is defined as the work done per unit time. Mathematically, it is expressed as: \[ P = \frac{W}{t} \] where \( P \) is power, \( W \) is work done, and \( t \) is time taken. ### Step 2: Define the work done by each man ...
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