There are some hills, plains, a few plateaus, and even parts of the Rocky mountains. Hope this helps!
The answer to six is C. Take up the same Volume and The answer to 7 is D. Pour the Liquid in a graduated Cylinder
Answer:
C) 21 m/s
Explanation:
The general formula of the Doppler effect is:
where
f' is the apparent frequency
f is the original frequency
v is the speed of the wave in the medium
is the velocity of the receiver, positive if the receiver is moving towards the source
is the velocity of the source, positive if the source is moving away from the receiver
Here we have
f = 440 Hz
f' = 415 Hz
v = 343 m/s
(the observer is stationary)
is positive since we are considering when the train has passed the observer, so it is moving away from him
So we can rewrite the formula as
And solving for , we find the speed of the train
The President is Xi Jinping
