Chapter 5 Flashcards
What is WORK DONE and what are its UNITS?
Work Done: When a force moves its point of application in the direction of the force.
Work Done = Energy Transferred (J)
What is the equation for WORK DONE?
W = Fx
Work Done = Force × Distance moved in the direction of the force.
What is ENERGY?
The capacity to do work.
It is a scalar quantity, it has magnitude, not direction.
What is ‘NO WORK’?
No work: If the net force is perpendicular to the motion then no work is done. If you push on an object and it doesn’t move, then no work is done. If an object’s kinetic energy doesn’t change, then no work is done.
How do you calculate WORK DONE AT AN ANGLE TO MOTION?
W = Fxcosø
What is KINETIC ENERGY?
Kinetic: Energy due to the movement of an object.
Ek = ½mv²
What is GRAVITATIONAL POTENTIAL ENERGY?
Gravitational potential energy: The capacity for doing work as a result of on an object’s position in a gravitational field.
Ep = mgh
What happens when a ball falls?
As a ball falls, gravitational potential energy converts into kinetic energy. When it hits the floor, energy is transferred into sound and heat energy. As the ball comes back up, kinetic energy converts back into GPE.
How do you calculate the VELOCITY of AN OBJECT FALLING WITH 0 AIR RESISTANCE?
Ek = Ep
½mv² = mgh
v² = 2gh
v = √2gh
State THE PRINCIPLE OF THE CONSERVATION OF ENERGY.
Principle of the Conservation of Energy: The total energy of a closed system remains constant: energy can never be created or destroyed, but it can be transferred from one form to another.
What is POWER?
Power is the rate at which work is done.
What is the equation for EFFICIENCY?
(Energy out ÷ Energy in) × 100
What is the eqaution for POWER and what are its UNITS?
P = Work Done ÷ Time
Power is measured in WATTS (W) or JOULES PER SECOND (J/s)
What is the equation for POWER FOR AN OBJECT MOVING AT A CONSTANT VELOCITY?
P = Fv
