Answer:
Doppler Theory
Explanation:
it's a theory regarding the change in wave frequency during the relative motion between a wave source and its observer.
Answer:
Less than 1 m
Explanation:
When objects are getting closer to each other there is a slight change in the wavelength that is being transmitted by either objects. This is known as the blue shift of waves. Here, the wavelength reduces.
In the opposite case the when objects are getting farther from each other there is a slight change in the wavelength that is being transmitted by either objects. This is known as the red shift. Here, the wavelength increases.
In this case the spaceship is getting close to Earth hence the wavelength will be lower than 1 m.
<h2>
The balloon is moving when it is halfway down the building at 20.78 m/s.</h2>
Explanation:
We have equation of motion v² = u² + 2as
Initial velocity, u = 0 m/s
Acceleration, a = 9.81 m/s²
Displacement, s = 0.5 x 44 = 22 m
Substituting
v² = u² + 2as
v² = 0² + 2 x 9.81 x 22
v² = 431.64
v = 20.78 m/s
Velocity at 22 m = 20.78 m/s
The balloon is moving when it is halfway down the building at 20.78 m/s.
