Answer:
Explanation:
A and B are in series , Total resistance = Ra + Rb
This resistance is in parallel with single resistor C
Equivalent resistance Re = Rc x ( Ra + Rb ) / [Rc + ( Ra + Rb )]
Now this combination is in series in single resistance D .
Total resistance = Rd + Re
= Rd + { Rc x ( Ra + Rb ) / [Rc + ( Ra + Rb )] }
Answer:
Snell's Law states
Ni sin i = Nr sin r
Judging from the question the source of the ray is in the water (directed up)
or NI = 1 / sin 49 Ni = 1.325 deg the critical angle
From inside the pond:
Nr = 1.325 * sin 45 / 1 = 94 deg
So refraction can occur outside the pond and you do not have total internal refection.
Hi alexander it is very true air pollution is only caused by human activity
Use the distance swan and the time elapsed in that interval.
Average velocity = distance / time
Average velocity = [4.0 m + 3.0m] / 3.2 s = 2.1875 m/s
Answer:
.
Explanation:
The frequency 
of a wave is equal to the number of wave cycles that go through a point on its path in unit time (where "unit time" is typically equal to one second.)
The wave in this question travels at a speed of 
. In other words, the wave would have traveled 
in each second. Consider a point on the path of this wave. If a peak was initially at that point, in one second that peak would be
How many wave cycles can fit into that ? The wavelength of this wave
gives the length of one wave cycle. Therefore:
.
That is: there are 
wave cycles in of this wave.
On the other hand, Because that of this wave goes through that point in each second, that wave cycles will go through that point in the same amount of time. Hence, the frequency of this wave would be
Because one wave cycle per second is equivalent to one Hertz, the frequency of this wave can be written as:
.
The calculations above can be expressed with the formula:
,
where
represents the speed of this wave, and 
represents the wavelength of this wave.
