Kinetic Energy Demonstrated with Crashing Spheres | Arbor Scientific
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- Опубликовано: 21 окт 2019
- Newton's Cradle illustrates for every action, there is an equal and opposite reaction. Thus, when one sphere is swung out and released, one is "kicked" out the other side, two when two spheres are released, and so on. But what happens when two large, Colliding Steel Spheres are smashed together? Watch this video to find out.
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Finally someone who understands kinetic energy. Would love to see you do another in-depth video. Especially if you understand how kinetic energy works with projectiles/ bullets
The other guy was like how did i got here
This is incredibly well made. I want some steel ball now.
Thank you! Glad you enjoyed it.
Excellent video, I will be using this with my homeschooled daughter. Thank you!!
Thank you!
My teacher used this to teach us in fourth grade ( few days ago )
Tomorrow I have the learning check about energy transfer and transformation so this helped
Hey um what school are you in cause me too
Excited sir, learn lot
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What are the difference between kinetic energy and potential energy? I discovered that all animate objects possess kinetic energy, while all inanimate object exhibit potential energy. Kinetic energy can be transformed into a potential energy, but the reverse is not true. Additionally, potential energy remains constant, regardless of whether it is in motion or at rest. ~Guadalupe Guerra
Pretty Serious
W22
All moving mass has two halves if it had just one half it would not be a mass regards Graham Flowers
Whos here because of school?
me
Me
What are the balls made out of ?
Steel.
Who only watches this cause of school😂
Some transform into heat and *sound* like we *_SAW_* earlier 🤦
That's just a phrase don't take it too literally ;)
There in no kinetic energy in those two metal balls when they are in motion there is force energy Mv squared kinetic energy is the energy that can do consistant work from a consistant force regards Graham Flowers
"Force energy" is what we call work. Integral F dot ds, where F is the force in question, and ds is the infinitesimal displacement as it moves along the path (we call displacement s, because d has another full time job), and dot refers to the dot product. For a constant force, this simplifies to F dot d. For aligned or opposite F and d, the dot product simplifies to simple multiplication of magnitudes and signs.
The kinetic energy is the energy they possess while in motion, equal to 1/2*m*v^2 for each ball. When coming to rest as the balls crash, that kinetic energy has to be transformed to some other form of energy, in this case, thermal energy and sound. To a lesser extent, the balls do bounce off of it, so some of it is converted to strain energy as the balls deform, and restored as kinetic energy.
It doesn't matter whether the force or rate of work done is constant or not. You might learn that initially as a way to keep the math simple. But in reality, the force can vary at every point along the way, and the same physical concept still applies. The only difference is, that multiplication (algebra) turns into integration (calculus), when the force is not constant.
@@grahamflowers I don't agree, since your first statement was incorrect, and misses the entire point of the concept of kinetic energy.
@@grahamflowers Are you asking where the 1/2 comes from in the kinetic energy formula? Because it isn't entirely clear what you are asking, and that is the only part of this that I think would have anything to do with the word half you keep mentioning. If I didn't understand your question, please clarify.
It comes from Calculus. You can prove it with a more generalized approach, where you'll end up determining that KE = integral momentum dot dv, but we'll keep it simple and consider a constant net force, so we don't need to think about dot products or any more calculus than necessary. Given: constant net force F, an object of mass m accelerates from rest through a distance d, in the same direction as the force. The work done on the object is W=F*d. For energy to be conserved, the KE in motion must equal the work done accelerating the object from rest. Thus KE=W=F*d.
Since the force is constant, this means we have constant acceleration, which means speed is given as v(t) = a*t + v0, and v0 being given as zero since it starts from rest. Integrate once to get position x(t) as a function of time, starting from an x-position equal to zero. You can do this graphically as the area of a triangle with base t, and height a*t, and get 1/2*a*t^2. Using N's 2nd law, we replace a with F/m, and get, x(t) = 1/2*F/m*t^2
After moving distance d, x(t) = d, and speed v(t) = v. Thus, d=1/2*F/m*t^2, and v=F/m*t. The work done is therefore, W=KE=1/2*F^2/m*t^2. Solve the other equation for t: t = v*m/F, and substitute: KE=1/2*F^2/m*(v*m/F)^2.
F^2 cancels, and one of the pairs of m's cancels. We are left with an m upstairs, a v^2 upstairs, and the leading constant of 1/2. Thus we derive KE=1/2*m*v^2.
@@grahamflowers I'm not waffling, I'm giving you the answer to what I perceive to be your question. Your question was unclear in the first place.
@@grahamflowers Just because 1/2 is in an equation, doesn't mean there even is another half. You might as well ask, why is the area of a circle equal to pi*d^2/4, and what happened to the other three quarters of pi*d^2?
The reason 1/2 is here, is that the object isn't moving at a constant speed from rest. If that were the case, the shape between the graph of speed vs time and the horizontal axis would be a rectangle, and we'd just multiply t by v to get the distance traveled during this time. That's the full a*t^2, but the upper triangle is fiction whose area does't apply to a situation when there is an acceleration from rest.
Instead, to get from rest to a given speed, it has to increase its speed from zero with a continuous function, in this case, a linear function. The area under a linear function y=A*x from the origin, is 1/2*A*x^2. Simple application of the power rule in Calculus, which you can also visually interpret as the area of a triangle, since the region under a linear graph is a triangle.
Since energy forms are independent of path, and only depends on initial and final states, this conclusion of KE=1/2*m*v^2 is valid in all situations of pure translation as long as v is insignificant relative to the speed of light. There is a proof of this that considers a generalized force and displacement, but it isn't necessary to use it, when the constant force method gets us the same result.
Lol only 44 comments
hi