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.
Answer:
Frequency = 3.19 * 10^14 Hz or 1/s
Explanation:
Relationship b/w frequency and wavelength can be expressed as:
C = wavelength * frequency, where c is speed of light in vacuum which is 3.0*10^8 m/s.
Now simply input value (but before that convert wavelength into meters to match the units, you do this by multiply it by 10^-9 so it will be 940*10^-9)
3.0 * 10^8 = Frequency * 940 x 10^-9
Frequency = 3.19 * 10^14 Hz or 1/s
Answer:
The correct answer is B.
The astronaut will know due to the light from the explosion.
Explanation:
Sound and vibrations require a medium such as air to travel through. Space, there is no air. Only a vacuum. So sound and vibrations are unable to travel. Light requires no medium to travel. It can go through a vacuum.
Therefore the Astronaut will see a bright flash of light as it travels from the explosion to outer space. It is also important to note that light can travel very far because nothing else interacts with its wave particles and as such, it cannot be impeded.
Cheers!
Answer:
ax = -3.29[m/s²]
ay = -1.9[m/s²]
Explanation:
We must remember that acceleration is a vector and therefore has magnitude and direction.
In this case, it is accelerating downwards, therefore for a greater understanding we will make a diagram of said vector, this diagram is attached.
![a_{x}=-3.8*cos(30) = -3.29 [m/s^{2}]\\ a_{y}=-3.8*sin(30) = -1.9 [m/s^{2}]](https://tex.z-dn.net/?f=a_%7Bx%7D%3D-3.8%2Acos%2830%29%20%3D%20-3.29%20%5Bm%2Fs%5E%7B2%7D%5D%5C%5C%20a_%7By%7D%3D-3.8%2Asin%2830%29%20%3D%20-1.9%20%5Bm%2Fs%5E%7B2%7D%5D)
