The answer 1 is
The best-known use of radio waves is for communication; television, cellphones and radios all receive radio waves and convert them to mechanical vibrations in the speaker to create sound waves that can be heard.Electromagnetic radiation is transmitted inwaves or particles at different wavelengths and frequencies.
the answer 2 is
Radio Waves: Instant Communication
Microwaves: Data and Heat
i think the answer number 3 is
It is all about wavelength versus tunnel diameter. The wavelength of GPS is about 20cm it would happily propagate in any normal tunnel if it could get in but the earth and other structures absorb it. AM radio (600kHz - 1500kHz) cannot propagate in any normal tunnel because the wavelength is too long (500m-200m) relative to the diameter, and thus gets reflected at the entrance. FM (100MHz ~ 3m) would propagate and it does for a while but then it suffers reflections
Speed of man towards West =2.5 m/s
Time to travel in the given direction = 1200 s
Total displacement towards west
Now speed of man towards East = 1 m/s
time to travel in east direction = 500 s
total displacement towards East
Now total displacement will be
so it is 2500 m towards west
Increasing its velocity will add to the kinetic energy more as the formula for kinetic energy is 0.5*m*v^2. (The speed will be squared making it greater)
Answer:
The effort distance (also sometimes called the “effort arm”) is shorter than the resistance distance. Mechanical advantage = |Fr/Fe | where | means “absolute value.” Mechanical advantage is always positive.
