Answer:
W = 0
Explanation:
As the satellite moves in a circle the force is perpendicular to the path, therefore the work that is defined by
W = F. r = f r cos θ
Since the force and the radius are perpendicular, the angle θ = 90º and the cosine 90 = 0, therefore there is no work for the circular motion.
W = 0
Explanation:
It took 
for the sound to reach the 1st wall and at the same time time, the same sound took 
to reach the 2nd wall. Assuming that the sound travels at 343 m/s, then let 
be the distance of the person to the 1st wall and 
be the distance to the 2nd wall. So the distance between the walls X is
The answer is so that everyone is measuring the same distance and counting that distance as the same everywhere. one example from real life why it is important to use standard units is the loss of the NASA mars orbiter. some people decided that the units were to be in metric and others thought that the units were in imperial (english) system. so the orbiter was lost.
let's eliminate some choices
A. to allow for consistientcy with measurement data:
not really, just make sure the instruments are accurate.
B. to use tools marked in customary units: this could be true because a custom is something that is accepted in a wide area and if it is standard, then it is customary so b is the answer
C. so they can keep measurement data secret: nope
D. to record with easier abbreviations: not really
the answer is B
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Do you have a question to ask ?
Answer: 60m/s
Explanation:
The wavespeed is the distance covered by the wave in one second. It is measured in metre per second, and represented by the symbol V
Wavespeed (V) = Frequency F x wavelength λ
i.e V = F λ
In the first case:
Wavespeed = 30 m/s
Frequency of sound = 6Hz
Wavelength = 5m
In the second case:
Wavespeed = ?
Frequency of sound = (2x 6Hz = 12Hz)
Wavelength = 5m (remains constant)
Apply V = F λ
Wavespeed = 12 Hz x 5m
Wavespeed = 60m/s
Therefore, when frequency is doubled, the speed is also doubled. Thus, the new speed of the wave is 60m/s
