These are the matched answers:
Explanation:
Given that,
Frequency of train horn, f = 218 Hz
Speed of train, 
The speed of sound, V = 344 m/s (say)
The speed of the observed person, 
(a) When the train approaches you, the Doppler's effect gives the frequency as follows :

(b) When the train moves away from you, the Doppler's effect gives the frequency as follows :

Hence, this is the required solution.
Answer:
9
Explanation:
A atomic number is the addition of every number
Answer:
time constant will decrease and steady state current will decrease on increasing the resistance
Explanation:
As we know that the EMF of cell is E which is used to connected across a resistor and an inductor.
So we will have

here we know that

now here we have

so if we increase the value of resistance of the wire then the time constant will decrease
and hence it will take less time to reach near the steady state value
also the steady state current will be smaller in that case
The simplest answer would be "acceleration due to gravity."
The exact value of this acceleration changes depending on which planet your on (for example).