The conservation of energy tells us that a bowling ball won’t swing higher than the initial height if there is no force added. But should we still believe that in a high risk situation? We are putting the laws of physics up to the test.
Caution: Do not try this at home without parental supervision.
Sir Isaac Newton says the total energy an object has will alway stay the same, unless you do something to change it (push or pull it). The system will start with a certain amount of potential energy, the energy possessed by a body by virtue of its position relative to others. When you raise the bowling ball to face level you are putting energy into the system in the form of work. Work is done when a force is applied to an object and the object is moved through a distance.
When you let go of the bowling ball and it starts to swing the ball will gain kinetic (or moving) energy, and lose it’s potential energy proportionally. This proportional loss and gain ensures the total energy of the system remains constant.
At the bottom of the pendulum (when the bowling ball is closest to the floor), all of the potential energy has been converted to kinetic energy. Therefore, the amount of kinetic energy in the ball is equal to the total energy of the system.
On the upswing of the pendulum, the kinetic energy will start to convert back into potential energy. This will happen until it reaches your face, where there is no longer kinetic energy, but instead the potential energy is equal to the total energy.
This pattern of gain and loss of potential and kinetic energy would continue on and on in perfect conditions. However, here on Earth, there is no such thing as perfect. With each swing of the pendulum there is a little bit of energy lost due to friction in the rope. This loss of energy will dampen each swing, causing the maximum height of swing to go down each time.
This is a great way to test yourself to see if you trust in the laws of physics. Would you have to guts to face up to the no flinch pendulum?
Written by: Mimi Garai