Kinetic Energy and Work Homework with Experiments and Calculations

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In summary, the experiment involves a ball with a mass of 0.1kg and initial kinetic energy of 1.25 J being pushed from point O and traveling through points D, C, E, F, and G. Friction is neglected and the players have springs that push with a constant force. The task is to complete a chart indicating the values of various variables at different points, calculate the ball's speed at point O and the work done by the net force from A to C, determine which hole the ball reaches, and add a Cartesian axis to the drawing. The equations needed for solving the problem include Ek=mv^2/2, W=Fx*cosα, W∑F=ΔEk,
  • #1
harelori
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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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  • #2
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?
 
  • #3
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
 
  • #4
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.
 
  • #5
The whole system I suppose, you think you can you help me solve it?
 

What is kinetic energy?

Kinetic energy is the energy an object possesses due to its motion. It is directly proportional to the mass of the object and the square of its velocity.

How is kinetic energy calculated?

Kinetic energy is calculated using the formula KE = 1/2 * m * v^2, where m is the mass of the object and v is its velocity.

What is the difference between kinetic energy and potential energy?

Kinetic energy is the energy an object has due to its motion, while potential energy is the energy an object has due to its position or state. Kinetic energy can be converted into potential energy and vice versa.

What is work?

Work is the measure of energy transfer that occurs when a force is applied to an object and causes it to move in the direction of the force. It is calculated by multiplying the force applied by the distance over which the force is applied.

How are kinetic energy and work related?

Kinetic energy and work are related in that work is required to change an object's kinetic energy. When a force is applied to an object, work is done, and the object's kinetic energy changes. Similarly, when work is done on an object, its kinetic energy changes as well.

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