Hello,
<span>A police car parked on the side of the highway emits a 1200 Hz sound that bounces off a vehicle farther down the highway and returns with a frequency of 1250 Hz.
How fast is the vehicle going?
Doppler equation formula: </span>ƒL = ƒS(v - vL)/(v - vS)
The wave returns with a frequency of 1250 Hz, the <span>echo frequency is higher; the car must be traveling towards the police car.
</span><span>The wave echo is coming back towards the police car at the same speed as the sound wave travels towards the moving car so t</span><span>he relative speed between the cars is half of the speed of the echo.
* </span><span>speed of sound equals about 337 m/s </span>
2v / 337 = (1250/1200) - 1
<span>2v = 14.04 m/s </span>
<span>v = 7.02 m/s
</span>
Thus, the vehicle is going 7.02 m/s.
Faith xoxo
<span>sometimes you can see yourself as well, due to refraction and reflection
</span>
Answer:
Time zone is one important factor in difference in location and this in turn affects the result of the resolution and rotation of shadow produced from the sun or other illumination.
Therefore someone at a place might see a clear large shadow due to shinny sun reflection and another a small or dull Shadow at same time if the intensity of the sun or lighting source is going down.
Explanation:
The closer a body/object is to a lighting source the larger the shadow it produces, and the farther the body the smaller the shadow produced.
Sample Response: The word “conservation” refers to an amount that is unchanged. The total amount of energy in the universe remains the same. The energy in the universe is in balance.
(a). The power of the candy bar is,
The time taken to play on 800 kJ energy of the candy bar is,
where E is the energy.
Substituting the known values,
As 1 minute is equal to 60 seconds,
Thus,
Thus, the time taken to play tennis on the 800 kJ energy is 30.3 minutes.
(b). By doing the exercise, the process of digestion of food inside our body increases. Thus, the exercise does not helps us to burn the calories. But it helps us to diggest the heavy meal like candy bar easily.
The time taken to digest the canndy bar or to utilise its energy is large because it takes a lot of time to burn small amount of food and make it digest quickly.