Download STATION ONE: What is Potential Energy? Potential energy is the

STATION ONE: What is Potential Energy?
Potential energy is the energy of an object that comes from its position, or condition,
rather than from its actual motion. It’s sort of like the stored energy that an object has. Its
opposite is kinetic energy, which comes from an object’s motion. Only moving objects
have kinetic energy, while a motionless object can have potential energy.
Imagine a baseball resting on top of a cliff. The ball isn’t moving, so it has no kinetic energy. However,
because the ball has the potential to gain a lot of kinetic energy if it falls off the cliff, it does have potential
energy. Now imagine that the ball falls off the cliff. As it moves downward, its potential energy is
transferred into kinetic energy. The further away an object is from the surface of the earth, the more
potential energy it has. In addition, the more massive an object is, the more potential energy it will have.
STATION TWO: How are potential and kinetic energy related?
The law of conservation of energy states that energy can’t be created or destroyed.
Instead, it can only be converted, or transformed, into a different type of energy.
Kinetic energy is the energy of an object in motion. Potential energy is the stored energy an object
contains. It depends on the object’s mass, as well as its position relative to the earth. A heavier object will
have more potential energy than a lighter one, and an object that’s high up on a cliff has more potential
energy than an object at sea level. As an object begins moving, its potential energy is converted to kinetic
energy. Imagine a baseball resting on top of a cliff. The ball isn’t moving, so it has no kinetic energy.
However, because the ball has the potential to gain a lot of kinetic energy if it falls off the cliff, it does
have potential energy. Now imagine that the ball falls off the cliff. As it moves downward, its potential
energy is transferred into kinetic energy. That’s how potential energy and kinetic energy work together!
STATION THREE: Can kinetic energy exist without potential energy?
That’s an awesome question. The law of conservation of energy states that energy can’t
be created or destroyed. Instead, it can only be converted, or transformed, into a different
type of energy. Kinetic energy can change to potential energy, which can change back to
kinetic energy. But kinetic energy can’t come from nowhere. However, potential and kinetic energy are
just two of many possible forms of energy. Kinetic energy can also come from thermal energy,
electromagnetic energy, elastic energy, etc. Talk to your science teacher to learn more!
STATION FOUR: How does a Yo-Yo work?
A yo-yo consists of two identical discs connected by an axle, which is tied to a piece of
sturdy string. The discs and axle can be made of plastic, wood, or metal. The person
playing with the yo-yo wraps the string around her middle finger and winds the string
completely around the axle. Then, the toy is thrown downward in a smooth motion. As the yo-yo unwinds,
it spins faster and faster. When the string is fully unwound, the yo-yo continues to spin and can be made
to return to the player's hand by a twitch of the wrist. If the string is loosely looped around the axle, the yoyo can spin and spin at the bottom of the string. This is called allowing the yo-yo to "sleep." Old-fashioned
yo-yos have the string tied tightly around the axle, only allowing the yo-yo to extend and return to the
player's hand. The yo-yo spins because of potential and kinetic energy.
Potential energy is the energy of an object that comes from its position relative to the earth, rather than
from actual motion. When a yo-yo is in a player's hand, it contains the potential energy to fall to the
ground and spin as it unwinds. Potential energy is the opposite of kinetic energy, which comes from an
object’s motion. Only moving objects have kinetic energy. As the yo-yo falls, its potential energy is
converted into kinetic energy. Because the yo-yo falls straight to the ground, it attains something called
linear momentum, or momentum in a straight line. It also builds something called angular momentum, or
momentum from rotating. Even when the string is fully unwound, the yo-yo keeps spinning because it has
built up angular momentum. At that point, it achieves something called gyroscopic stability. That means
that because it is spinning, the yo-yo resists changes to its axis of rotation. Because the yo-yo is spinning
with stability, people can do all kinds of neat tricks and the yo-yo will keep spinning!
STATION FIVE: How does a mousetrap car work?
A mousetrap car is a car powered only by a spring-loaded mousetrap. The mousetrap
holds elastic potential energy. It is attached to a string, which is wound around the axle of
the back wheels. When the tension is released and the trap snaps shut, the potential
energy turns into kinetic energy. The string is pulled, the wheels turn, and the car begins to move.
You can learn more about mousetrap cars by checking out a book from your school library, asking an
adult to help you do an Internet search, or asking your science teacher for help!
STATION SIX: Kinetic Energy: What is it?
Kinetic energy is created from movement or motion. Any time you exert force on an
object, like throwing a ball or closing a door, you’re creating kinetic energy. You cannot
exactly destroy kinetic energy, but you can stop it by simply putting an end to any motion
or force being exerted on an object.
STATION SEVEN: What does the word “Kinetic” mean?
The word “kinetic” comes from the Greek word “kinesis,” which means “motion.” That’s
why kinetic energy is the energy of an object that’s moving!
STATION EIGHT: What does friction and kinetic energy have to do with roller coasters?
Friction and kinetic energy have a lot to do with roller coasters! A roller coaster usually
doesn’t have a motor. Instead, it’s lifted up to the top of the first hill by a chain on the track
itself, gaining potential energy the higher up it travels. As the coaster rolls downhill, the
potential energy changes into kinetic energy, and this kinetic energy allows the coaster to go around the
entire track. However, the coaster doesn’t simply keep going forever. Friction, caused by the wheels
moving on the track and the coaster moving through the air, gradually decreases the kinetic energy. This
causes the coaster to slow down. Brakes also use friction to completely stop the roller coaster at the end
of the ride!
STATION NINE: What exactly is energy?
Energy can mean lots of things, actually. It’s everywhere! In physics, energy refers to the
ability to do work—usually that has something to do movement, or action. Energy comes
in a number forms. They include mechanical potential energy, which is like energy that’s
stored in a system and waiting to come out; kinetic energy, which is the energy in a moving system;
chemical energy, which is energy that’s stored in chemical bonds between atoms; electrical energy, which
is energy from interactions between charged particles; thermal energy, which relates to heat energy of
molecules; and nuclear energy, which is energy that’s stored between the particles within atomic nuclei.
Light and other forms of electromagnetic radiation such as gamma rays or X-rays are also thought of as a
form of energy. And actually, the physicist Albert Einstein showed that in fact, pretty much all mass is a
form of energy too!
STATION TEN: What is the Law of Conservation of Energy?
The Law of Conservation of Energy states that energy can’t be created or destroyed in a
system. Instead, it must be converted, or transformed, into another type of energy. There
are lots of different kinds of energy, including kinetic, potential, heat, light, chemical,
mechanical, and nuclear. You can see the idea of the transformation of energy when you think about
lighting a match. What happens is that the chemical energy stored in the match is converted into heat
energy and light energy.