I think it is d I hope this help you if not let me know if it is not right
Answer:
The depth of focus achievable with those lenses is small.
Explanation:
A larger aperture makes it much harder to focus on more than one object. When using a telephoto lens (the ones the question is referring to), the depth of focus is very small. For example, using a telephoto lens to take a photo of a runner might get the runner in focus, but certainly not the track, or the audience behind them. If you look at photos, especially older photos, of Olympians in almost any sport you can see this.
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Explanation:
Q = mc∆T
= (0.34 kg)(94 J/kg-°C)(25°C)
= 799 J
All it does is lets him pull in a more convenient direction to raise the load. It has no effect on the required force.
The decibel system of sound intensity operates by a logarithmic scale, meaning that sound intensity increases exponentially in relation to the decibel rating.
For decibels, the equation between intensity and the dB equivalent is:
dB = 10log(i),
where “i” is the intensity of the sound. The ten in front of the log means that an increase in ten dB results in a tenfold increase in sound intensity; for example, a 30 dB sound is ten times softer than a 40 dB sound.
In this case, a sound with a dB of 80 would be 1000 times more intense than a 50 dB sound, so the decibel rating of B is 80.
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