Energy, Work and Power Flashcards
What is energy, SI unit (scalar quantity)
Energy is the ability/capacity to do work, Joules (J)
What is kinetic energy
-Moving objects have kinetic energy
-Kinetic energy can be used to do work
What is gravitational potential energy
-The energy a body possesses due to its position above the ground
Principle of Conservation of Energy
The principle of conservation of energy states that energy can neither be created nor destroyed but can only be converted from one form to another. The total energy in an isolated system is constant.
Formula for total energy input
Total energy input = useful energy output + wasted energy output
Formula for efficiency
Efficiency = (useful energy output/energy input) x 100%
Formula for kinetic energy
KE = 1/2 (m) (v^2)
KE = 1/2 x mass x velocity^2
Formula for gravitational potential energy
GPE = (m)(g)(h)
GPE = mass x gravitational force x height
What is work
The work done by a constant force on an object is the product of the force and the distance moved by the object in the direction of the force
Formula for work done, SI unit
W = F x d
Work done = Force x distance
SI unit: Joules (J)
What is power
Power is defined as the rate of work done or rate of energy conversion
Formula for power, SI unit
power = work done/time taken
power = energy/time taken
SI unit: watt (W)
