Answer:
Δ
= 84 Ω,
= (40 ± 8) 10¹ Ω
Explanation:
The formula for parallel equivalent resistance is
1 /
= ∑ 1 / Ri
In our case we use a resistance of each
R₁ = 500 ± 50 Ω
R₂ = 2000 ± 5%
This percentage equals
0.05 = ΔR₂ / R₂
ΔR₂ = 0.05 R₂
ΔR₂ = 0.05 2000 = 100 Ω
We write the resistance
R₂ = 2000 ± 100 Ω
We apply the initial formula
1 /
= 1 / R₁ + 1 / R₂
1 /
= 1/500 + 1/2000 = 0.0025
= 400 Ω
Let's look for the error (uncertainly) of Re
= R₁R₂ / (R₁ + R₂)
R’= R₁ + R₂
= R₁R₂ / R’
Let's look for the uncertainty of this equation
Δ
/
= ΔR₁ / R₁ + ΔR₂ / R₂ + ΔR’/ R’
The uncertainty of a sum is
ΔR’= ΔR₁ + ΔR₂
We substitute the values
Δ
/ 400 = 50/500 + 100/2000 + (50 +100) / (500 + 2000)
Δ
/ 400 = 0.1 + 0.05 + 0.06
Δ
= 0.21 400
Δ
= 84 Ω
Let's write the resistance value with the correct significant figures
= (40 ± 8) 10¹ Ω
The runner has initial velocity vector

and acceleration vector

so that her velocity at time
is

She runs directly east when the vertical component of
is 0:

It's not clear what you're supposed to find at this particular time... possibly her position vector? In that case, assuming she starts at the origin, her position at time
would be

so that after 10.4 s, her position would be

which is 19.9 m away from her starting position.
Answer:
B
Explanation:
The mass of something before it's been processed is the same as it's mass after the process.
the layers of rocks, the ancient treasures that are at the bottom of the sea, how old the coral is. But I don't think they determined how old it is, how would the dinosaurs that lived in water swim or any drink water. I don't know if this helps but hopefully it does. Also scientist have made advanced tech that could help with the age determination of the ocean floor.