travel through a vacuum at the speed of light. Other waves need a medium; sound waves need molecules that vibrate.
Answer:
Intensity of the transmitted radio wave is 5.406 x 10⁻⁶ W/m²
Explanation:
Given;
power of radio transmitter, P = 63.2 kW = 63200 W
distance of transmission, r = 30.5 km
Intensity of the transmitted radio wave is calculated as follows;

where;
I is the intensity of the transmitted radio wave
Substitute the given values and calculate the intensity of the transmitted radio wave;

Therefore, Intensity of the transmitted radio wave is 5.406 x 10⁻⁶ W/m²
A
The horizontal force cancels out. The two 4Ns go in opposite directions. So they don't affect the outcome.
The Vertical force is 6N up - 2 N down = 4 N Up
Answer 4 N up
B
The horizontal and vertical forces cancel out. Each gives 3N - 3N =0
The net force is 0
C
You only have horizontal forces on this one
5N - 3N = 2N
The answer is 2N to the right.