Kinetic Energy and Work Homework with Experiments and Calculations

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The discussion revolves around a homework problem involving kinetic energy and work calculations for a ball in motion. Key points include the calculation of the ball's speed at point O, which is determined to be 5 m/s, and the analysis of forces and energy changes at various points in the experiment. Participants clarify that the mechanical energy referred to in the chart includes both potential and kinetic energy of the ball. The conversation also addresses assumptions about the spring's force remaining constant and the neglect of rolling or spinning effects. Overall, the focus is on understanding the dynamics of the ball's motion and the energy transformations involved.
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Homework Statement


*The experiments drawing is attached.
m=0.1kg
Ek at point O (the moment the ball is being pushed) = 1.25 J
D (0 ; 0) , C (0 ; 0.05), E (0.25 ; 0), F (0.50 ; 0), G (0.75 ; 0)
Friction is neglected

1.Complete the chart by typing if the value of each variable is rising / decreasing / constant / equals to zero. (attachment added)
2.Calculate the balls speed at point O.
3.Calculate the work of ∑F that has been working on the ball from A to C. ( W∑F )
4.The ball reaches one of the holes G/F/E - calculate which one it reaches.
5.Add Cartesian axis on the drawing, locate in it the points :C,D,E,F,G and add to the drawing the route of the ball from point C until the point he touches the ground.
6.Players has springs that pushes the spring with a constant F that is higher/lower than the original spring. Which one does one has to use for the ball to fall after point G? (The distance of AA' stays the same)

*I'm having difficulties with basically everything*

Homework Equations


Ek=mv^2/2
W=Fx*cosα
W∑F=ΔEk
1/2kΔx^2
W=-ΔU
U=mgh

The Attempt at a Solution



1. At point A'O: v:rising , a:rising, ∑F:constant, Mechanic Energy: rising
At point OC: v:constant , a:0, ∑F:constant, Mechanic Energy: constant.
From point C until the ball touches the ground: v:constant, a:rising, ∑F:rising, Mechanic Energy: constant.

2.
Ek=mv^2/2 => 1.25 = 0.1v^2/2 => 2.5= 0.1v^2 => v=5 m/s

*If the question has anything missing - please write the answer you would have done just without placing the number in the variable. As in a parametric answer.
 

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Seems to me there is some verbal description of the experiment missing at the start.
Are we to ignore rolling/spin?
As the spring expands from AA' to AO, is the force in the spring increasing, decreasing, or staying the same?
In the chart, which energy does E refer to? Is it just the energy in the ball (PE+KE) or the energy of the whole system, or something else?
You have calculated the velocity of the ball at O (assuming not rolling). What will be the speed at C? What dynamical equations do you know for the flight of the ball after C?
 
We are to ignore the rolling/spinning.
We assume that while the spring expands the force is staying the same.
In the chart, E refers to Mechanic Energy (Ep+Ek).
The speed at C should be 5 m/s,
and the afterwards I suppose it's to be projectile motion
 
harelori said:
We are to ignore the rolling/spinning.
We assume that while the spring expands the force is staying the same.
You're told that? Please post all the text describing the experiment.
In the chart, E refers to Mechanic Energy (Ep+Ek).
Yes, but just of the ball or of the whole system (i.e. including the spring)?
The speed at C should be 5 m/s,
and the afterwards I suppose it's to be projectile motion
Yes.
 
The whole system I suppose, you think you can you help me solve it?
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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