Energy, Work And Power Flashcards
What is work
Force applied over distance
What are the units for work
Joules
What are the units for energy
Joules
What are the units for power
Watts
When is no work done
No work is done if no distance is covered in the direction of the force applied
In order for work to be done what must be true about force and distance
Force and distance must be in the same direction
What is a joule
Newton* meters
Amount of energy needed to apply one Newton of force/ one meters distance
Any time work is done what must be used
Energy must be used to do work
Define energy
Energy is the ability to do work
What are the different categories of energy
Kinetic and potential
What is kinetic energy
Kinetic energy is the energy if motion, ex
Sound, light, heat, moving objects, electricity
What is potential energy
Potential is the energy of position or stored energy
Ex
Chemical energy, gpe, energy of position, but
What is the formula for kinetic energy and what variable matters most
KE= 1/2mV(2)
Most influential is velocity
What is the formula for potential energy and what variable is most valuable
GPE= w*h
Height is the most influential
What is the law of conservation go energy
Law of conservation of energy states that energy cannot be crated or destroyed only converted from one form to another
How does the law of conservation of energy relate to potential and kinetic energy
In the roller coaster lab, PE is converted to KE as the marble rolls down hill, KE is converted to PE as the marble rolls up hill
If a roller coaster cars mass is doubled what happens to the amount of kinetic and potential energy that the car will have
Doubling the mass of the car doubles the potential energy at the top and therefore doubles the speed at the bottom
If the cars velocity is doubled what will happen to the kinetic and potential energy
Doubling the velocity will mean the car has 4x as much energy
As an object falls what happens to the value of potential energy
Potential decreases as an object falls (less hieght=less PE)
As an object falls what happens to the value of kinetic energy
KE increases as an object falls because it’s velocity is increasing as PE is being converted into KE
What is the energy transformation in lighting a match
Chemical energy to heat and light
What is the energy transformation in turning in a light
Electrical energy to light
What is the energy transformation in starting a car
Chemical energy to kinetic energy of moving energy
What is the energy transformation in walking up stairs
Chemical energy to kinetic energy of moving body
What is the energy transformation in playing a piano
Chemical energy to kinetic and sound, moving fingers to moving strings into sound
What is the formula for work
w=f*d
What is the formula for power
P= w/t
P= f*d
——–
T
If you have a 50kg object and lift it a distance of 10 meters how much work so you do on the object, how much power of you do it in four seconds?
W= 5,000j P= 1250watts
If you exert 150 joules of energy in 15 seconds, what is your power
P= 10 watts
What is the difference between work and power
Work is done when energy is converted from one form to another, power is how fast the energy is converted or how fast the work is done
What is gpe
Potential to fall
