The answer is A. <span>Some work input is used to overcome friction. </span>
Answer:
Option A is correct.
The wires will be arranged in order of increasing resistance.
Explanation:
The resistance of a wire is given by
r = (ρl)/A
where r = resistance of the wire
ρ = resistivity of the wire
L = length of the wire
A = cross sectional area of the wire
Provided all the other parameters are constant, resistance is inversely proportional to cross sectional area
r ∝ (1/A)
And the the cross sectional Area of the wire increases with increase in thickness & decreases with thickness
So, decreasing thickness ----> Decreasing Cross sectional Area ----> Increasing resistance.
Answer:
The speed of Susan is 2.37 m/s
Explanation:
To visualize better this problem, we need to draw a free body diagram.
the work is defined as:
here we have the work done by Paul and the friction force, so:
Now the change of energy is:
Since velocity is a speed and a direction, there are only two ways for you to accelerate: change your speed or change your direction—or change both. If you're not changing your speed and you're not changing your direction, then you simply cannot be accelerating—no matter how fast you're going.
