The general formula to calculate the work is:

where F is the force, d is the displacement of the couch, and
is the angle between the direction of the force and the displacement. Let's apply this formula to the different parts of the problem.
(a) Work done by you: in this case, the force applied is parallel to the displacement of the couch, so
and
, therefore the work is just equal to the product between the horizontal force you apply to push the couch and the distance the couch has been moved:

(b) work done by the frictional force: the frictional force has opposite direction to the displacement, therefore
and
. Therefore, we must include a negative sign when we calculate the work done by the frictional force:

(c) The work done by gravity is zero. In fact, gravity (which points downwards) is perpendicular to the displacement of the couch (which is horizontal), therefore
and
: this means
.
(d) Work done by the net force:
The net force is the difference between the horizontal force applied by you and the frictional force:

And the net force is in the same direction of the displacement, so
and
and the work done is

Answer:
.2166 repeating or 21.66% repeating
Explanation:
In attached image
B. is it i just got done this in class like two weeks ago hope it helps
Assume there is a smallest rational integer that has the following form: a/b
Then observe that we can define a/(b+1), which is strictly less than a/b because its divisor is bigger and is rational because it is the product of two numbers. Due to the contradiction created by our original claims that a/b is the smallest rational number that is possible, we might conclude that there is no such thing as the smallest rational number.
There can therefore be no smallest rational number because we may always define a smaller rational number than the one we now possess.
<h3>What is Rational number ?</h3>
Any number that can be expressed as a ratio is considered reasonable. It is therefore possible to represent it as a fraction when the numerator and denominator are both full numbers.
Learn more about Rational number here:
brainly.com/question/12088221
#SPJ4
I hope the wire is not wound too tightly around the bar magnet.
The device will generate electrical energy when the bar magnet
is moving in or out of the coil of wire.