Answer:
z = 0.8 (approx)
Explanation:
given,
Amplitude of 1 GHz incident wave in air = 20 V/m
Water has,
μr = 1
at 1 GHz, r = 80 and σ = 1 S/m.
depth of water when amplitude is down to 1 μV/m
Intrinsic impedance of air = 120 π Ω
Intrinsic impedance of water = 
Using equation to solve the problem

E(z) is the amplitude under water at z depth
E_o is the amplitude of wave on the surface of water
z is the depth under water



now ,


taking ln both side
21.07 x z = 16.81
z = 0.797
z = 0.8 (approx)
The answer is D) Velocity
In a block and tackle, some friction in the pulleys will reduce the mechanical advantage of the machine. To include friction in a calculation of the mechanical advantage of a block and tackle, divide the weight of the object being lifted by the weight necessary to lift it.
Hope this helps
Answer:
Yes
Explanation:
Kinetic energy is K.E1/2mv2 so that means it is directly proportional to mass and velocity.
The resistance of the cylindrical wire is
.
Here
is the resistance,
is the length of the wire and
is the area of
cross section. Since the wire is cylindrical
.
Comparing two wires,

Dividing the above 2 equations,

Since 
The above ratio is

We also have,

The current through the Silver wire will be 4.23 times the current through the original wire.