Answer:
your answer for this question is B
Answer:
Objects; waves.
Explanation:
Waves interact with objects and other waves. Thus, waves are used on objects such as mobile phones and can be transformed from one form to another.
There are various types of waves in our physical environment such as gamma rays, x-rays, ultraviolet waves, radio waves etc.
Radio waves can be defined as an electromagnetic wave that has its frequency ranging from 30 GHz to 300 GHz and its wavelength between 1mm and 3000m. Therefore, radio waves are a series of repetitive valleys and peaks that are typically characterized of having the longest wavelength in the electromagnetic spectrum.
Basically, as a result of radio waves having long wavelengths, they are mainly used in long-distance communications such as the carriage and transmission of data. Some examples of communication technologies that uses radio waves are radio set, mobile phones, television etc.
Answer:
B ) 1.5 m/s
Explanation:
For the apparent frequency reflected by enemy submarine , the Doppler effect formula is
F = F₀ ( V + v) / (V - v)
F anf F₀ are real and apparent frequency , V and v are velocity of sound and velocity of enemy submarine respectively.
ΔF / F₀ = 
Put ΔF = 200; F₀ = 100000 and V = 1482
200 / 100000 = 
v = 1.5 m s⁻¹ .
