Answer:
a) Height of the antenna (in m) for a radio station broadcasting at 604 kHz = 124.17 m
b)Height of the antenna (in m) for radio stations broadcasting at 1,710 kHz =43.86 m
Explanation:
(a) Radiowave wavelength= λ = c/f
As we know, Radiowave speed in the air = c = 3 x 10^8 m/s
f = frequency = 604 kHz = 604 x 10^3 Hz
Hence, wavelength = (3x10^8/604x10^3) m
λ
= 496.69 m
So the height of the antenna BROADCASTING AT 604 kHz = λ /4 = (496.69/4) m
= 124.17 m
(b) As we know , f = 1710 kHz = 1710 x 10^3 Hz (1kHZ = 1000 Hz)
Hence, wavelength = λ = (3 x 10^8/1710 x 10^3) m
λ= 175.44 m
So, height of the antenna = λ /4 = (175.44/4) m
= 43.86 m
Answer:
C.
m
Explanation:
We are given that
Weight of board=w=10 N
Length of board=L=5 m
Tension in the string=T=3 N
Applied upward force=F=7 N
We have to find the distance at which its left wedge would they need to place this force in order for the board to be in static equilibrium.
Let r be the distance at which its left wedge would they need to place this force in order for the board to be in static equilibrium.
The board is uniform therefore, the center of board is the mid- point of board.
Therefore, the lever arm of weight=
Now, the torque exerted by the weight of the board

The torque exerted by applied force=
In static equilibrium
The sum of rotational forces=0

The two rotational force act in opposite direction therefore,

Substitute the values


m
Hence, option C is true.
Beryllium has a mass number of 9 and 4 protons. To find the number of neutrons you need to subtract the number of protons from the mass number. so...
neutrons = mass - # protons
neutrons = 9 - 4 = 5
Answer:
fossil fuels are natural and limited, nuclear is man made and more toxic
Explanation: