The concept required to solve this problem is the optical relationship that exists between the apparent depth and actual or actual depth. This is mathematically expressed under the equations.

Where,
Depth of glass
Refraction index of water
Refraction index of glass
Refraction index of air
Depth of water
I enclose a diagram for a better understanding of the problem, in this way we can determine that the apparent depth in the water of the logo would be subject to



Therefore the distance below the upper surface of the water that appears to be the logo is 4.041cm
Steps 1 and 2)
The variables are W = work, P = power, and t = time. In this case, W = 9514 joules and P = 347 watts.
The goal is to solve for the unknown time t.
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Step 3)
Since we want to solve for the time, and we have known W and P values, we use the equation t = W/P
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Step 4)
t = W/P
t = 9514/347
t = 27.4178674351586
t = 27.4 seconds
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Step 5)
The lawn mower ran for about 27.4 seconds. I rounded to three sig figs because this was the lower amount of sig figs when comparing 9514 and 347.
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Note: we don't use the mass at all
Yes, it is true, both mass spectrometry and infrared spectroscopy involve interaction of molecules with electromagnetic waves. ;Mass spectrometry method is used to determine the mass of a substance while infrared spectroscopy is used to determine the functional groups in molecules. Both methods involve the analysis of electromagnetic light interaction with molecules.