Forces and Motion
Vocabulary
force
Definition: A push or a pull on an object
Context: The ball was hit with enough force to send it into
the bleachers.
friction
Definition: A force that resists motion between two bodies in
contact
Context: Rougher surfaces create more friction than smooth
ones when an object comes in contact with them.
gravity
Definition: The natural force that attracts any two objects
with mass toward each other
Context: Earth's gravity pulls on anything that is not held up
by some other force.
speed
Definition: The rate of motion
Context: The speed of the ball is determined by measuring
how far it travels in a certain amount of time.
velocity
Definition: The speed of an object moving in a specific
direction
Context: The car's velocity was 55 miles per hour,
eastbound.
acceleration
Definition: The rate of which an object changes it velocity
Context: Acceleration can be positive or negative
depending on whether the object is speeding up or slowing
down.
Inertia
Definition: The ability of an object to remain in motion or
remain at rest unless acted upon by an outside force
ENERGY TERMS
Energy- the ability to do work
Potential- stored energy that has the ability to do future
work
Kinetic-energy of motion
FORMS of ENERGY
“CLEMNT”
Chemical- stored in particles that make up food and other
fuels
Light-the sun is the major source of light energy. Light
energy converts to chemical energy and electrical energy
Electrical- the movement of charged particles, batteries
and power of plants that burn fuel. This energy travels
through our homes through wires and cables
Mechanical- moving objects have this energy. This energy is
the sum of potential and kinetic. Turning on a toy is a good
example
Nuclear- energy that comes from tiny particles that come
together to create huge amounts of energy
Thermal- motion of tiny particles. This comes in the form of
stoves, heaters and matches. The faster the particles move
the warmer the substance gets.
CONCEPTS to THINK ABOUT
How can you tell that something has moved?
You can compare the object’s new position to its original
position
What is speed?
The distance an object moves in a certain amount of time.
How can a force affect motion?
A force can start or stop motion. A force can change the
direction of motion.
How does inertia affect motion?
Inertia keeps moving objects in motion
What makes motion change?
A push or pull; forces
What forces act on motion?
Gravity, friction