Energy, Work, and Simple Machines Flashcards
Efficiency
Can be calculated by comparing a machine’s output work to its input work
Machine
A device that changes the magnitude or the direction of a force
Compound machine
Consists of 2 or more simple machines linked so that the resistance force of one machine becomes the effort force of the second machine
Resistance force
the force exerted by a machine
watt
a unit of power defined as 1 joule per second
effort force
the force exerted by a person on a machine
work-energy theorem
states that the work done on an object equals the change in kinetic energy of the object
energy
the ability of an object to produce a change in itself or its surroundings
kinetic energy
the energy that results from the motion of an object
power
the rate of doing work
mechanical advantage
the ratio of the resistance force of a machine to its effort force
why is gasoline called a ‘miracle’ in the film
Gas is relatively cheap, it leaves no ash or residue, has a high yield
joule
the SI unit used for work
ideal mechanical advantage
calculated by comparing the effort distance to the resistance distance
work
when an applied force is multiplied by the distance through which the force is applied
What makes electric cars still expensive
Batteries are expensive
What does the area under the force-displacement graph represent?
the work done on the object
what are 2 major advantages of natural gas as an energy source compared to the other fossil fuels
Natural gas is less expensive
environmental friendly; burns cleaner
What is the equation for finding work?
w = fd
Work and energy are measured in?
Joules
do you think nuclear power is a safe form of energy
it is very safe because they can withstand drastic weather and the plants are very secure
Explain the relationship between work and energy
Energy is the ability to do work. When you do work to move an object, you’re changing the object’s energy