Card Set Information
When is work done?
when a force causes a change in motion of an object
What is work
is a force that is applied to an object mutiplied by the distance of movement of the object
If we apply a force on an object that does not move. Is there any work being done
no work has been done
Sitting and looking at a computer screen is this work
Tapping on the keyboard and making the keys move is this work
yes, because your fingers are moving and applying a force in the direction of motion (down)
What units are work and energy expressed in ?
What is power?
Power is the quantity that measures the rate at which work is being done. How fast work is being done
One watt is the amount of power required to do 1 _______ in 1 _______
joule of work in 1 second of time
What is energy (4)
the ability to do work
a measure of how much work is done
a word to describe the power and effort of a force
measured in joules
What are the two main types of energy
Kinetic energy and Potential energy
What is potential energy ?
is stored energy
Coaster has PE when it is at the ____ of the hill. EVen if it isn't moving yet, it may if a force is applied and it begins to move
What is gravitational potential energy (GPE)
is the energy of an object due to its position above the surface
What is kinetic energy?
is the energy due to an object's motion and is active energy
A rock as it falls off of a cliff. Potential energy or Kinetic energy
What is the Law of Conservation of Energy
The Law of Conservation of Energy says energy cannot be created or destroyed, but it can be transformed from one form to another.
What is the law of conservation of energy similar to ?
law of conservation of mass/matter
What are the forms of energy
: motion- Potential and Kinetic, includes sound
: light and electricity
This is described as work divided by the time it takes to perform that work .
This is also known as kgm/sec2. It is the unit used to measure force
This is the energy of motion
This is one of the major reasons that machines never can reach a 100% effiency rating
This is the unit used to designate work done.
this is the advantage of a high-horsepower automobile over a lower-horsepower automobile
This is the ability to do work
James Watt compared his steam engine to these when he was trying to market the new engine
To determind the potential energy of an object, you must know the acceleration due to gravity, mass, and the ____
To compute a kinetic energy, you need mass and _____.
These are devices for mutiplying force or changing
this is determined by mutiplying the force times the distace in which an object is moved
mass is caculated in units of _______________ when determining potential energy
This is equal to the intial velocity okus acceleration mutiplied by time
In an energy tranfer, the same type of energy moves to a __________ object.
Type of potential energy of objects at a height
Energy of appliances such as stereos and computers
In an energy transformation, the object remains the __ but the energy changes to a different type
Type of potential energy of springs and rubber bands
Form of energy produced by musical instuments
Ability to do work
Law of ______________ of Energy states that energy cannot be created nor destroyed in a chemical reaction. It can be changed from one form to another
Type of energy that is stored
unit of energy
Energy of radiant objects such as fire
Form of potential energy in food and dynamite.
In a light bulb, electrical energy changes to light energy. This is an example of an energy _____________-.
Form of energy of nuclear reactions
When cooking on a stove, the heat energy moves from the stove to the saucepan to the cooking food. This is an exmaple of an energy ________