Explain why the action represented in the image is impossible

It isn't

me same monke as you...

Is it? If it was a regular pulley, the boy would need half the force of his weight to lift himself up assuming frictinless pulley

Plus the weight of the chair. Make the cable massless

>tries to solve physics problem
>removes laws of physics to solve problem.

Single pully doesn't reduce force, just changes the angle.

Leverage

you can yank on the crank but you cant wank when you plank.

I don't believe it is, if the child and chair are firmly together and equal to total weight of the spring weight.

Question is, what is the action here?

Wait a sec. The two can't be equal, because the child/chair would have to weigh more otherwise the device would balance out, right? The spring and string should be level, unless the child started lower and then grabbed the string. But then one weight would still be greater, and...

No, wait. If they were in equilibrium it just means neither is moving in this case. Which means that the child/chair is the same weight, as the chair is not appearing to be influenced here. Provided the system was made as pictured after the child got on, they should be possible. My above thing is stupid.

So... question is, what is the action? Grabbing the string shouldn't have any impact, since they don't appear to be exerting any force on it...

Okay OP, it's been too long since physics. What's the answer?

Here's:
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First we draw a figure (a free body diagram) with all forces acting on the boy and on the seat and write down the equations of motion for them.
The forces acting on the boy (left) and on the seat (right)

The forces acting on the boy:
N⃗ 1
...the normal force exerted on the boy by the seat
T⃗ 1
...the tension force by which the rope pulls on the boy
F⃗ G1
...the weight of the boy
The forces acting on the seat:
N⃗ 2
...the normal force exerted on the seat by the boy
T⃗ 2
...the tension force by which the rope pulls on the seat
F⃗ G2
...the weight of the seat
The equation of motion for the boy:
T⃗ 1+N⃗ 1+F⃗ G1=m1a⃗ (1)
The equation of motion for the seat:
T⃗ 2+N⃗ 2+F⃗ G2=m2a⃗ (2)
To write the equations of motion in a scalar form we choose a suitable frame of reference. We choose the axis y to point upwards in the direction of the tension forces.
The forces acting on the boy (left) and on the seat (right)
The scalar equation of motion for the boy:
T1+N1−FG1=m1a(3)
The scalar equation of motion for the seat:
T2−N2−FG2=m2a(4)
Since we consider the pulley to be massless it has no moment of inertia and thus has no effect on the tension of the rope. According to Newton’s third law the magnitudes of the tension forces are equal:
|T⃗ 1|=|T⃗ 2|
Once again according to Newton’s third law the normal force exerted on the seat by the boy is of the same magnitude as the force exerted on the boy by the seat:
|N⃗ 1|=|N⃗ 2|
Using these relations we can rewrite the equations (3) and (4) as:
T2+N2−FG1=m1a(5)
T2−N2−FG2=m2a(6)
Calculation of the acceleration a.
We add up the equations (5) and (6):
2T2−FG2−FG1=(m2+m1)a
and express the acceleration as:
a=2T2−FG2−FG1m2+m1=
a=2T2−m2g−m1gm2+m1
a=2T2m2+m1−m2g+m1gm2+m1=2T2m2+m1−g(7)
For the given numerical values we get:
a=(2⋅60032+64−9.81)m⋅s−2=(120096−9.81)m⋅s−2
a=(12.5−9.81)m⋅s−2=2.69m⋅s−2

Attached: chlapec_na_kladce_3.page.tagged.gif (295x410, 16.96K)

(cont)
Note: The resulting acceleration is positive. Therefore, the boy and the seat are moving upwards in the direction of the y-axis. If we have chosen the y-axis to point downwards the acceleration would be negative.

Calculation of the magnitude of the normal force N2.

We express N2 from the equation (6):

N2=T2−FG2−m2a

N2=T2−m2g−m2a

and substitute the acceleration given by the equation (7):

N2=T2−m2g−m2(2T2m2+m1−g)

N2=T2−2T2m2m2+m1

N2=T2m1+T2m2−2T2m2m2+m1

N2=T2(m1−m2m2+m1)(8)

For the given numerical values we get:

N2=600(64−3232+64)N=600⋅(32)96N=6003N=200N

if he flips the board up and uses jerks the rope down he can shove it all the wall into his ass and pull the line out his trachae, shitting himself through the wheel catch and having the hook feed through his intestines while eating his own arms and eventually the slack of the rope and then there will be nothing

Basically, if the boy pulls down on the string, the weight is shifted to the string with the spring, that is if both sides are of equilibrium.
When the boy lets go of the string the boy and weight is then returned to equal on both sides.

If the boy jumps up and down on the seat, then there is force being applied by gravity+momentum, which in turns makes the boy and the seat move downward.

If the boy stops jumping up and down, he will return back to equilibrium.

he's basically on a balanced scale.