Author: Maddie Van Beek
Energy: What you get when you eat a whole bag of Skittles and six Mountain Dews? Not exactly. What IS energy? Let's find out!
Energy: What you get when you eat a whole bag of Skittles and six Mountain Dews? Not exactly. What IS energy? Let's find out!
Ok, so what are the two main types of energy? Put them into your own words!
So remember, energy is never actually LOST--it is just transferred or converted into other TYPES of energy. To go a little further into what potential and kinetic energy actually are, let’s watch this video! It may be an old cartoon, but the reality of energy has not changed!
- Potential
- Kinetic
So remember, energy is never actually LOST--it is just transferred or converted into other TYPES of energy. To go a little further into what potential and kinetic energy actually are, let’s watch this video! It may be an old cartoon, but the reality of energy has not changed!
Examples of potential and kinetic energy:
Dropping a ball (or anything, really!)
Dropping a ball (or anything, really!)
Look at the path this basketball takes. Before the ball is dropped (far left) it is full of potential energy. As the ball falls, it loses potential energy and gains kinetic energy. Right before the ball hits the ground, it is the exact opposite of when it was initially dropped. The ball's kinetic energy is at an all-time high and has low potential energy. But that energy is quickly converted as it bounces back upwards. Just remember, when potential energy is high, kinetic energy is low. When kinetic energy rises, potential energy falls.
Stretching a rubber band or shooting an arrow: The farther I stretch the rubber band, the more potential energy it has. When I let go of the rubber band, the potential energy immediately transfers into kinetic energy. This concept is very similar to archery. The stretched bow is full of potential energy; when the string is released, the bow's potential energy transfers into the arrow's kinetic energy.
A roller coaster: As the roller coaster car climbs upwards, it is gaining potential energy. At the top of the peak, potential energy is at its height. As soon as the car drops downwards, all that gained potential energy is converted to kinetic energy. Kinetic energy is at an all-time high at the very bottom of the drop, and then it begins to convert back to potential energy. Kinetic energy increases at the same rate that potential energy decreases. They are INVERSES of one another.
Still confused? Think again of a roller coaster. If the roller coaster starts at the top with 100 Joules (Joules are the units used to measure both kinetic and potential energy) of potential energy, the point at the end of drop would have 100 Joules of kinetic energy, because that’s when the roller coaster would be at its fastest. A moment later, when the roller coaster starts going up again, that kinetic energy goes down, and what increases? That’s right, potential energy.
Take a moment to think of a few more examples. When have you seen potential energy? When have you seen kinetic energy?
Let’s demonstrate this!
YOU WILL NEED:
Hypothesize: Does the height from which a ball is dropped affect how high a ball will bounce?
Here's what to do!
Now, we will do the same with a tennis ball.
Hypothesize: Does the size of the ball affect how high it will bounce?
Repeat steps 1-5 with the tennis ball.
Did you get the same results? Explain.
Let's try something new! First, hold the basketball. Next, hold the tennis ball in place directly on top of the basketball. Drop both balls at the same exact time and watch what happens!
You should have seen the basketball hit the ground and the tennis ball hit the basketball, which then sends the tennis ball flying! When does the tennis ball bounce higher--on its own, or when it hits the basketball? Record your observations.
Why did the basketball cause the tennis ball to come bouncing back up? Would this work the same way if you dropped the balls in the opposite order? If you’re not sure, try it out and see what happens!
Based on your previous observations, which ball has more kinetic energy, the tennis ball or the basketball? Why do you think this is?
Force
When you dropped the tennis ball and the basketball, you saw two forces at work. First, both the tennis ball and the basketball had a force acting upon them--gravity. Second, when the basketball hit the ground, the energy from the impact was transferred to the tennis ball, creating contact force.
What is force, you ask? Force is the push or pull of an object that happens when an interaction between two objects occur. Picture two vehicles crashing into each head on at the same speed. If one vehicle is a semi-truck and one is a Mini Cooper, which vehicle will have more force enacted upon it? Well, think of the tennis ball as the Mini Cooper and the basketball as the semi-truck. That’s just a start on understanding force and Newton’s Laws, but that's enough for now!
Until next time--May the force be with you!
Take a moment to think of a few more examples. When have you seen potential energy? When have you seen kinetic energy?
Let’s demonstrate this!
YOU WILL NEED:
- Basketball
- Tennis ball
- Tape measure or yard stick
Hypothesize: Does the height from which a ball is dropped affect how high a ball will bounce?
Here's what to do!
- Use the tape measure or yard stick to measure three feet up from the ground.
- Lift the basketball to the three foot mark.
- Drop the ball and pay attention to how it bounced. Record the height. Do this three times and find the average height.
- Now, measure five feet up from the ground. Repeat steps 1-3.
- Did the height from which the ball was dropped affect the height that the ball bounced? Explain.
Now, we will do the same with a tennis ball.
Hypothesize: Does the size of the ball affect how high it will bounce?
Repeat steps 1-5 with the tennis ball.
Did you get the same results? Explain.
Let's try something new! First, hold the basketball. Next, hold the tennis ball in place directly on top of the basketball. Drop both balls at the same exact time and watch what happens!
You should have seen the basketball hit the ground and the tennis ball hit the basketball, which then sends the tennis ball flying! When does the tennis ball bounce higher--on its own, or when it hits the basketball? Record your observations.
Why did the basketball cause the tennis ball to come bouncing back up? Would this work the same way if you dropped the balls in the opposite order? If you’re not sure, try it out and see what happens!
Based on your previous observations, which ball has more kinetic energy, the tennis ball or the basketball? Why do you think this is?
Force
When you dropped the tennis ball and the basketball, you saw two forces at work. First, both the tennis ball and the basketball had a force acting upon them--gravity. Second, when the basketball hit the ground, the energy from the impact was transferred to the tennis ball, creating contact force.
What is force, you ask? Force is the push or pull of an object that happens when an interaction between two objects occur. Picture two vehicles crashing into each head on at the same speed. If one vehicle is a semi-truck and one is a Mini Cooper, which vehicle will have more force enacted upon it? Well, think of the tennis ball as the Mini Cooper and the basketball as the semi-truck. That’s just a start on understanding force and Newton’s Laws, but that's enough for now!
Until next time--May the force be with you!
References:
https://en.wikipedia.org/wiki/Forms_of_energy
http://www.sciencekids.co.nz/experiments/bouncingballs.html
http://www.physicsclassroom.com/class/newtlaws/Lesson-2/The-Meaning-of-Force
http://www.eschooltoday.com/energy/kinds-of-energy/what-is-kinetic-energy.html
Image and Video Credits, in order of appearance:
The Science Asylum, 2013. What is Energy REALLY?! Uploaded from YouTube on 9/4/2016. https://youtu.be/jCrOtF7T4HE
cassiw2, 2009. The story of potential and kinetic energy. Uploaded from YouTube on 9/4/2016. https://youtu.be/7K4V0NvUxRg
Bartz & Maggs, 2007. Bouncing ball strobe edit. Uploaded from Wikimedia Commons on 9/4/2016.
https://upload.wikimedia.org/wikipedia/commons/thumb/3/3c/Bouncing_ball_strobe_edit.jpg/1024px-Bouncing_ball_strobe_edit.jpg File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made.
Psalter, 1324. Longbowmen. Uploaded from Wikimedia Commons on 9/4/2016.
https://upload.wikimedia.org/wikipedia/commons/a/a7/Longbowmen.jpg File released into the Public Domain.
BrandonR, 2005. Wooden roller coaster txgi.
https://upload.wikimedia.org/wikipedia/commons/3/30/Wooden_roller_coaster_txgi.jpg
Uploaded from Wikimedia Commons on 9/4/2016. File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made.
Utchay Endre, 2008. May the force be with you. https://youtu.be/vSJNeXrCbE4 Uploaded from YouTube on 9/4/2016.
https://en.wikipedia.org/wiki/Forms_of_energy
http://www.sciencekids.co.nz/experiments/bouncingballs.html
http://www.physicsclassroom.com/class/newtlaws/Lesson-2/The-Meaning-of-Force
http://www.eschooltoday.com/energy/kinds-of-energy/what-is-kinetic-energy.html
Image and Video Credits, in order of appearance:
The Science Asylum, 2013. What is Energy REALLY?! Uploaded from YouTube on 9/4/2016. https://youtu.be/jCrOtF7T4HE
cassiw2, 2009. The story of potential and kinetic energy. Uploaded from YouTube on 9/4/2016. https://youtu.be/7K4V0NvUxRg
Bartz & Maggs, 2007. Bouncing ball strobe edit. Uploaded from Wikimedia Commons on 9/4/2016.
https://upload.wikimedia.org/wikipedia/commons/thumb/3/3c/Bouncing_ball_strobe_edit.jpg/1024px-Bouncing_ball_strobe_edit.jpg File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made.
Psalter, 1324. Longbowmen. Uploaded from Wikimedia Commons on 9/4/2016.
https://upload.wikimedia.org/wikipedia/commons/a/a7/Longbowmen.jpg File released into the Public Domain.
BrandonR, 2005. Wooden roller coaster txgi.
https://upload.wikimedia.org/wikipedia/commons/3/30/Wooden_roller_coaster_txgi.jpg
Uploaded from Wikimedia Commons on 9/4/2016. File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made.
Utchay Endre, 2008. May the force be with you. https://youtu.be/vSJNeXrCbE4 Uploaded from YouTube on 9/4/2016.
