Work Energy And Power Flashcards
Def Work
It is the product of Force and Displacement in the direction of the force
Give the formula for work
W = F x s
W = Joules F = Newton s = displacement
Define a Joule
It is the amount of work done when a force of one newton is applied over a distance of one metre.
Work is done only when:
- A force acts on a body continuously
- The displacement through which the object moves is in the direction of the force
- There is a resistance to the motion of the object.
Define a system
It is the matter that has been specified for study and experimentation
Def kinetic energy
It is the energy that a body has by virtue of it’s motion
Define gravitational energy
It is the energy that a body has by virtue of its position
Define a Joule
It is the amount of work done when a force of one Newton is applied over a distance of one metre
Def power
Is the rate at which work is done
Def a Watt
Is the unit of power used when one Joule of work is done in 1 second
State the law of Conservation of energy
Energy cannot be created or destroyed, but can be transferred into an equivalent amount of another form of energy
State the principle of conservation of mechanical energy
It atates that for an isolated system
the sum of gravitational potential energy and the kinetic energy of a body in a vertical plane remains constant
Def an inelastic collision
Is one in which momentum is conserved, but kinetic energy is not
Def elastic collision
Is one where both momentum and kinetic energy are conserved
Give the formula for Efficiency
Efficiency = useful energy output/ energy input x 100
