Explanation:
Echoes occur due to the reflection of sound from any obstacle, but not all the reflected sound waves lead to the phenomenon of echo. For the echo to be heard it actually depends upon the human perception as well, human ears can encounter the difference between the sound wave directly form the source and the reflected sound waves only if there is a minimum time gap of one-tenth of a second. For this time gap in the atmosphere at normal temperature and pressure the obstacle must be at least 7 meters away from the sound source.
Explanation:
<h2> Answers</h2>
1.Electromagnetic waves
2.Electromagnetic radiation
3.Electromagneticwaves
The correct answer is C. Mercury and Mars have the same gravitational force
Explanation:
This chart compares the different features of two planets in our solar system (Mercury and Mars). In this chart, the only numerical value or feature that is the same for both planets is gravity because for both planets gravity is 1.7 m/s2. This implies the gravitational force or the force that attracts objects towards the center of the planet is the same or that objects are pulled with the same force in both planets. Moreover, this factor depends on others such as mass, density, among others.
Answer:
<u>1.8kJ</u>
Explanation:
Formula :
<u>Energy used = Power x time</u>
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Given :
⇒ Power = 30 W
⇒ Time = 1 minute = 60 seconds
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Solving :
⇒ Energy used = 30 W × 60 s
⇒ Energy used = 1,800 J
⇒ Energy used = <u>1.8kJ</u>
Answer:
Your question is incomplete
