5. Work, energy, and power Flashcards
(11 cards)
What is the equation for work done?
W = Fx
W = work done / J
F = force / N
x = distance moved in the direction of the force / m
Define 1J
The work done when a force of 1N moves its point of application 1m in the direction of the force
What is energy?
The capacity to do work
What are the different forms of energy?
- Kinetic energy
- Gravitational energy
- Chemical energy
- Elastic potential energy
- Electrical potential energy
- Nuclear energy
- Radiant / electromagnetic energy
- Sound energy
- Internal energy
What is the principle of conservation of energy?
The total energy of a closed system remains constant: energy can never be created or destroyed only transferred from one form to another
What is the equation for kinetic energy?
Ek = 1/2 mv^2
What is gravitational potential energy?
The capacity for doing work as a result of an objects position in a gravitational field
What is the equation for gravitational potential energy?
Ep = mgh
What is power?
The rate of work done
What is the equation for power?
P = W / t
P = power / W or Js^-1
W = work done / J
t = time / s
What is the equation for efficiency?
Efficiency = useful output energy / total input energy x 100%
