<span>The drag force acts opposite to the direction the cars' motion and the propelling force is in the direction of the motion. These are the two forces acting on the car and since they are both equal and opposite in direction, they cancel out each other. Thus, the car is able to move at a constant speed without changing its direction or momentum.</span>
The original frequency of horn of Car A is 1071 Hz.
Explanation:
Doppler effect describes the change in the frequency of sound waves with respect to the observer. As the sound waves emitted from a source need to travel the air medium to reach observer, it will undergo loss in energy. So there will be change in its frequency compared to original frequency. Depending upon the direction of travel of source and observer the shifting of frequency will vary.
Here vo is the observer velocity and vs is the velocity of the source. So Vo = 15 m/s as car B is the observer and Vs = 35 m/s as car A is the source. And f is the frequency of sound wave at source that is car A.
Similarly, the doppler shift in frequency is the frequency of sound heard by car B which is f' = 1140 Hz. And v is the speed of sound that is v = 343 m/s
1140 = 
f = 1140/1.0649= 1071 Hz.
Thus, the original frequency of horn of Car A is 1071 Hz.
B. carbon + oxygen -- carbon dioxide
Explanation:
The best equation that describes a reaction where carbon combines by burning in the presence of oxygen to produce carbon dioxide is:
carbon + oxygen -- carbon dioxide
Every chemical reaction is made up of reactants and products
Reactants are the species on the left hand side of an equation, the products are those on the right hand side.
The reactants combines chemically to give produces.
The kind of reaction depicted above is a synthesis or combination reaction where two species combines to gives a product or more;
C + O₂ → CO₂
learn more:
Chemical reaction brainly.com/question/3953793
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Answer:
current
Explanation:
According to ohm’s law, resistance is equal to voltage divided by current.
Answer:
3.87 or 3.9 mg
Explanation:
2.7h * 60mins = 162mins
number of 1/2 lives = 162/22= 7.364
amount remaining = 639(1/2)^7.364 = 3.8796
answer = 3.87 or 3.9
