This isn't a math question and should be in the science section. However, I will still answer the question. The answer is choice B.
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Here's a further breakdown
A. False. The radiation or energy from the sun can travel through air or else you wouldn't feel the sun's rays. Also, plant life wouldn't be alive without that energy going through the air.
B. True. The rays travel through a vacuum of space. If they couldn't travel through space, then the same problem comes up as in choice A: the issue of not feeling the sun's rays.
C. False. They rays have different frequencies. Because there are many wavelengths (see choice D below), this means there are different frequencies. Recall that f = 1/w where f is the frequency and w is the wavelength.
D. False. The rays are made of different wavelengths. The visible light portion is what we can see, though there is a lot more to the electromagnetic spectrum (eg: ultraviolet light).
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So once again, the answer is choice B
Answer:
Step-by-step explanation:
Power is defined by work over time. In physics, work can be defined as the energy transferred over from an applied force over some distance. As a formula:
, where F = force applied and d = distance that force is applied over.
*It is worth noting that F must be parallel to the distance travelled. If it is perpendicular, no work is done, and if it is at an angle, find the parallel component and use that for F.
In this case, the force applied must counter the force of gravity on Martha, which is given by 
, where m = Martha's mass and g = gravitational constant 9.8 m/s/s. Therefore, 
. Since she raises her body 4.0 meters, the work done must be 
.
Since power is equal to work over time and t = 2.3 seconds, we have:
(to two significant figures)
I would say 7,000,000,000,000,000,000,00,00,,0000,00
