<span>The equation that relates Wavelength & frequency of electromagnetic waves is :
Velocity (c) = Wavelength (λ) * frequency (f) ------ (1)
Electromagnetic wave velocity (c) = Speed of Light = 3 * 10^8 m/s
From (1),
Wavelength , λ = c / f
λ= (3*10^8)/(980*10^3)
λ = 306.12 m
Minimum height of the antenna for effective transmission = λ * 0.5 = 306.12*0.5
Answer : 153 m (rounded off)</span>
Answer:
<h3>0.42s</h3>
Explanation:
Velocity = Displacement/time
Displacement of the horse is the distance covered in a specified direction
Total distance of the horse towards the right = 15m + 20m = 35m
Total distance of the horse towards the left = 4m
Displacement = Distance towards the right - Distance towards the left
Displacement = 35m-4m
Displacement = 31m
Time taken = 74seconds
substitute the values gotten into the velocity formula
average velocity = 31m/74s
average velocity = 0.42m/s
Hence the magnitude of its average velocity is 0.42s
I don’t know what it’s is
Answer:
<h2>1.5 ohms</h2>
Explanation:
Power is expressed as P = V²/R
R = resistance
V = supplied voltage
Given P = 600W and V = 30V
R = V²/P
R = 30²/600
R = 900/600
R = 1.5ohms
magnitude of its resistance is 1.5ohms
For this case we first think that the skateboard and the child are one body.
We have then:
1 = jug
2 = skateboard + boy
By conservation of the linear amount of movement:
M1V1i + M2V2i = M1V1f + M2V2f
Initial rest:
v1i = v2i = 0
0 = M1V1f + M2V2f
Substituting values
0 = (7.8) (3.2) + (M2) (- 0.65)
0 = 24.96 + M2 (-0.65)
-24.96 = (-0.65) M2
M2 = (-24.96) / (- 0.65) = 38.4 kg
Then, the child's mass is:
M2 = Mskateboard + Mb
Clearing:
Mb = M2-Mskateboard
Mb = 38.4 - 1.9
Mb = 36.5 Kg
answer:
the boy's mass is 36.5 Kg
