Given:
speed of passing pony 5 m/s
frequency of the sound produced: 221 Hz
speed of sound 342 m/s
Let us use the Doppler Shift Formula:
Where the <span>source is moving away from the observer at rest
</span>
f' = (v / v+vs) f
Where, vs<span> = Velocity of the Source,</span>
v = Velocity of sound or light in medium,
f = Real frequency,
f' = Apparent frequency.
f'= [342 m/s / (342 m/s+5m/s)] * 221 Hz
f' = 0.9856 * 221Hz
f' = 217.8176 Hz or 218 Hz
The observed frequency <span>of the hooves after the pony has passed your position is 218 Hz.</span>
Given:
Sample 1:
Chloroform is 
12 g Carbon
1.01 g Hydrogen
106.4 g Cl
Sample 2:
30.0 g of Carbon
Solution:
mass of chloroform from sample 1:
12 + 1.01 +106.4 =119.41 g
Now, for the total mass of chloroform in sample 2:
mass of chloroform 

mass of chloroform = 119.41 
= 298.53 g
<span>Scientists can see the effect of black holes on nearby stars.
So, option B is your answer.
Hope this helps!
</span>
<span>Four waste materials from copper ore processing are: ore minerals, unwanted rock or gangue, uranium, and pyrite/sulfide minerals. Ore minerals are contained in rock and have potential to be economically extracted, gangue may contain silicate minerals for which there is no economic value, uranium is a frequently-occurring radionuclide found in ore bodies, and pyrite and sulfide minerals may be found in tailings piles during copper processing.</span>