C.reproducing is think and if wrong I'm so very sorry
<h2>
a) Equivalent resistance is 143 Ω</h2><h2>
b) Potential difference is 71.5 V</h2>
Explanation:
When resistors are connected in series, effective resistance is given by

Here
R₁ = 21Ω
R₂ = 58Ω
R₃ = 64Ω
a) 
Equivalent resistance is 143 Ω
b) We know
Potential difference = Current x Resistance
V = IR
I = 0.5 A
R = 143Ω
Substituting
V = 0.5 x 143 = 71.5 V
Potential difference is 71.5 V
Answer:
The unit is the barn, which is equal to 10-28 m^2 or 10-24 cm^2
Explanation:
The standard unit for measuring a nuclear cross section (denoted as σ)
<span>First, water evaporates from the ocean to the atmosphere, then... put each step in the correct order.
</span>Second- atmospheric circulation advects the water.
Third- water condensates to form clouds.
Fourth- precipitation falls from clouds to the land.
Fifth- some water stored as snow or ice.
Sixth- water either ±ows along the surface in rivers and lakes or infiltrates the ground.
Seventh- water returns to the ocean.