one of the property of radio waves is that they have long wavelength. due to their long wavelength , they undergo diffraction around the mountains and thus the waves spread around the mountain. this makes them eligible to be used for long distance communication. they can coded and decoded also . that is why they are used in television and radio system
Answer:
f = 7.97 x 10⁶ Hz = 7.97 MHz
Explanation:
The speed of a wave is given by the following formula:

where,
v = speed of the ultrasound wave through human tissue = 1540 m/s
f = frequency of ultrasound wave required = ?
λ = wavelength of ultrasound waves = smallest detail required = 0.193 mm
λ = 0.193 mm = 1.93 x 10⁻⁴ m
Therefore,
<u>f = 7.97 x 10⁶ Hz = 7.97 MHz</u>
Answer:
3.True. The magnitude of momentum is the same
Explanation:
Let's propose the solution of the problem
The initial moment is
p₀ = m v
The final moment
= m (-v)
p₀ = -
Now we can review the claims
1. False. We see that the moment module is the same, but its direction changes
2. False. The impulse is a vector
3.True. The magnitude of momentum is the same
Explanation:
Let
and 
The sum of the two vectors is


The difference between the two vectors can be written as


Answer:
5) Displacement = +3.125 m
Displacement is in the same direction as the force vector.
6) Force = -53.89 N
Force is in an opposite direction relative to the displacement.
Explanation:
5) We are given;
Force; F = 160 N.
Workdone; W = +500 J
Now, formula for workdone is;
W = Force × displacement
Thus, displacement = Work/force
Displacement = 500/160
Displacement = +3.125 m
Thus, displacement is in the same direction as the force vector.
6) We are given;
Displacement; d = 18 m.
Workdone; W = -970 J
Like in the first answer above,
Workdone = Force × Displacement
Thus;
Force = Workdone/Displacement
Force = -970/18
Force = -53.89 N
Since force is negative and displacement is positive, it means force is in an opposite direction relative to the displacement.