What is the kinetic energy and velocity of the aluminum
sphere in...

Question

What is the kinetic energy and velocity of the aluminum
sphere in Problem 1.4 at the moment it hits the ground? (Assume
that energy is conserved during the fall and that 100%
of the sphere’s initial potential energy is converted to kinetic
energy by the time impact occurs.)

Accepted Answer

Hey everyone in this example, we have a ball falling from the top of the table. And at one point during the fall, the kinetic energy and potential energy of the ball are 12 jewels and 68 jewels respectively. We need to calculate the total kinetic energy of the ball just before it strikes the floor. So recognize that they tell us that the kinetic energy is equal to 12 jewels And that our potential energy of the ball is equal to 68 jewels. So what we want to recognize is that just before the ball strikes the floor, all of that potential energy converts to energy of motion being kinetic energy as the ball falls. And so we would assume that therefore none of the energy is lost as heat. And so with that being said, we would find our total kinetic energy. Bye. Taking down that assumption and saying that we would take 12 jewels And add that to now 68 jewels of kinetic energy, Which would give us a total of 80 jewels. And so this will correspond to answer choice D as our final choice to complete this example. And again, that is because our potential energy for our ball converts to kinetic energy as soon as the ball, or just before the ball strikes the floor. So I hope that everything we reviewed was clear. If you have any questions, please leave them down below. And I will see everyone in the next practice video

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