Download Study Vocabulary for Objects in Motion

Objects In Motion Vocabulary
Words
Types of
Energy
Definitions
Renewable Energy Resources are natural resources that can replenish themselves over
time.
Non-Renewable Energy Resources are natural energy resources that exist in limited
supply and cannot be replenished in a timely manner
Sources
of
Energy
Energy
A measurement of an object's ability to do work.
Work
Work is defined as applying a force in order to move an object in a given direction.
Note- Work can only be done to a system by an external force
+More work that is done by an object, the more energy it exerts.
+Since energy is equal to work, the unit for both is the same, the Joule (J).
1 Joule = 1 Newton-mete
The amount of work done is the change in the amount of energy that the system will
Work
Equation experience. This is given by the equation:
Objects In Motion Vocabulary
Work
Types of Work
Definitions
+Positive If the object moves in the same direction as the direction of the
force. Ex-Pushing a desk across the room.
+Negative If the object moves in the direction opposite the direction of the
force. Ex-Pushing at a rock & it does move.
Kinetic Energy
Dependent On
+ Mass & velocity.
Speed
The speed of an object over a distance. Ex.-35mph
Velocity
The speed & direction of an object. Ex.-40 mph East
Calculating Kinetic
Energy
Kinetic Energy
Problem
A car, which has a mass of 1,000 kg, is moving with a velocity of 5 m/s. How
much Kinetic Energy does the car possess?
Potential Energy
Forms
Gravitational—is energy stored based on where the object is located.
+Greater height—more gravitational potential energy.
+Lower height—less gravitational potential energy.
Elastic Energy—is energy stored when something is stretched. Once you
release the stretched object, the energy is released. Ex—Rubber bands
Objects In Motion Vocabulary
Word
Gravitational Potential Energy
Influenced By
Calculating Gravitational
Potential Energy
Example - Calculating
Gravitational Potential Energy
Definition
Mass, gravity, and height.
GPE = mgh
A basketball, who’s mass is 0.5 kg, is held at a height of 2 m above
the ground.
GPE = mgh
GPE = (0.5 kg)(9.8 m/s2)(2 m)
GPE = 9.8 J
Elastic Potential Energy
Determined By
+The elasticity of the material
+How far it is stretched or compressed.
Calculating Elastic Potential
Energy
EPE = Elastic Potential Energy (J)
k = spring constant (N/m)
x = distance of stretch or compression (m)
Example - Calculating Elastic
Potential Energy
A spring, which has a spring constant of 10 N/m, is stretched a
distance of 1 m.
EPE = kx2
EPE = ( )(10 N/m)(1 m)2
EPE = ( )(10 N/m)(1 m2)
EPE = (5 N*m)
EPE = 5 J
Mechanical Energy
The total energy possible is the Potential Energy (PE) and the
Kinetic Energy (KE) added together.
(PE + KE)i = (PE + KE)f
Objects In Motion Vocabulary
Work
Mechanical Energy
Definition
The total energy possible is the Potential Energy (PE) and the Kinetic Energy
(KE) added together.
(PE + KE)i = (PE + KE)f
Conservation of
Energy
If the amount of energy that we start with "Ei" and the amount we
end up with as "Ef" then we would say that if no energy is added to
or taken away—energy conservation has occurred in the system.
TEi = TEf
What if the Total If the total amount of energy that we start with, Ei, does not equal the total
Mechanical
amount of energy that we end up with, "Ef", then mechanical energy is not
Energy is not
naturally conserved.
equal at the
beginning and the
TEi = TEf
end?
Because of this, the system is not a closed system, and the
surroundings are allowed to interact with the system. This means
that there is an outside for that is acting on the system over some
distance.