Answer:
Explanation:
a.) Dose equivalent is:
b.)
c.) The dose equivalent is:
C: if it senses unequal currents
In the absence of a diagram the general answer to the roller coaster scenario is as follows. Energy is always conserved in nature and if we exclude the energy losses due to friction in the moving parts and surfaces of the roller coaster, the sum of kinetic and potential energy of the car will always equate to the same number, called the mechanical energy.
As the rollercoaster moves you can imagine energy flowing between kinetic and potential states. The highest potential energy will be the highest and slowest point on the track, this will also be the lowest kinetic energy state. Similarly, the highest kinetic energy will be the lowest and fastest point on the course, which is also the point of lowest potential energy.
<span>Sure. Picture this: Your friend is
wearing prescription sunglasses outside. He looks at you through them,
and the light from you is refracted on the way through the glasses, to
correct for his vision. At the same time, if you look at his glasses,
you can see yourself reflected in them. Same light ... from you to his
sunglasses. Part of it passed through the lenses and got refracted.
Another part of the light got reflected back to you, just like hitting a
mirror, and you saw yourself.</span>
As the question is about changing in frequency of a wave for an observer who is moving relative to the wave source, the concept that should come to our minds is "
Doppler's effect."
Now the general formula of the Doppler's effect is:
-- (A)
Note: We do not need to worry about the signs, as everything is moving towards each other. If something/somebody were moving away, we would have the negative sign. However, in this problem it is not the issue.
Where,
g = Speed of sound = 340m/s.
= Velocity of the receiver/observer relative to the medium = ?.
= Velocity of the source with respect to medium = 0 m/s.
= Frequency emitted from source = 400 Hz.
= Observed frequency = 408Hz.
Plug-in the above values in the equation (A), you would get:
Solving above would give you,
= 6.8 m/s
The correct answer = 6.8m/s