Rubber band, elastic, spring
The best and most correct answer among the choices provided by your question is the second choice or letter B.
The researchers’ conclusion was not justified because t<span>he control group was not treated the same as the experimental group.</span>
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The work done to stretch the spring will be 112 J.
<h3>What is spring force?</h3>
The force required to extend or compress a spring by some distance scales linearly with respect to that distance is known as the spring force. Its formula is
F = kx
The given data in the problem is;
F is the spring force =?
K is the spring constant= 8.5 N/m
x is the length by which spring got stretched = 1.2m
The work is done to stretch the spring is;

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In series circuit, Req = R₁ + R₂ + R₃ + ···
In parallel circuit, 
<h3>Q7.</h3>
total resistance in the upper branch = R₂ + R₃ = R₂ + 2


R₂ + 2 = 12
R₂ = 10Ω
<h3>Q8.</h3>


Req = 1.7Ω
Answer:
- No, this doesn't mean the electric potential equals zero.
Explanation:
In electrostatics, the electric field
is related to the gradient of the electric potential V with :

This means that for constant electric potential the electric field must be zero:





This is not the only case in which we would find an zero electric field, as, any scalar field with gradient zero will give an zero electric field. For example:

give an electric field of zero at point (0,0,0)