<u>Answer</u>
3 Ohms
<u>Explanation</u>
when the resistors are in series, the resistance in the circuit increases. For example, if two resistors, R1 and R2 are in series, the combined resistance is R1+R2.
When connected in parallel, the total resistance is the reciprocal of (1/R1 + 1/R2)
In this case the resistors are in parallel.
Total resistance = (1/12 + 1/4)⁻¹
= (1/3)⁻¹
= 3 Ohms
V = d ÷ t --> bc d=vt
V = (76+54)÷(2+5) = 130÷7 = 18.57km/hr
Answer:

Explanation:
Using the conservation of energy we have:

Let's solve it for v:

So the speed at the lowest point is 
Now, using the conservation of momentum we have:

Therefore the speed of the block after the collision is 
I hope it helps you!
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)
Answer:
Its not really possible I don't think. UNLESS! You fall into a manhole then find a wirling vortex in the sewers! : )
Explanation: