Work
In order for Work to be done, what must be true of Force and Displacement
they must be PARALLEL to each other
If an object is not moving it has _____ KE
ZERO or NO
Potential energy is the energy due to ____
Position or Height
True or False?
Energy is never created nor destroyed, it is just transferred into other forms of energy.
The unit for Power is called the ________.
What is WATT?
True or False?
In order for Work to be done, an object must be moved some Distance as a result of a Force; and they must be perpendicular to each other.
What is FALSE
As a roller coaster goes down a hill, the Kinetic Energy ______________.
INCREASES
As a roller coaster goes down a hill, its Potential Energy __________________?
DECREASES
Which of the following is a form of Mechanical Energy?
a. Internal
b. Electrical
c. Chemical potential
d. Gravitational potential
What is- D- gravitational potential
If a lifting job done two different ways requires the same amount of work, how is power affected?
it depends on the TIME that it takes to complete the job
A car slows down on a flat road.
Is work being done?
YES
Ball A has double the mass of Ball B.
What is the ratio of KE of A to B ?
(... Remember KE = 1/2 m v2
2:1
The three variables that impact Potential Energy.
What is MASS, HEIGHT and GRAVITY?
Friction converts kinetic energy to ______.
What is HEAT?
If the Distance an object is pushed doubles while the Time it takes to do the Work is cut in half, what happens to the Power
the Power becomes 4 times greater
P = F d / t
What is the unit for Work?
Joules, N*m or Kg-m2/s2
If the Velocity of an object triples, then its KE will be _______.
(Remember: KE = 1/2 m v2)
9 times greater
For Earth, Potential energy is always measured relative to _____
an arbitrary zero level (for Earth, usually assumed to be GROUND LEVEL)
If friction is negligible, the what will be the kinetic energy of an arrow that is shot out of a bow that has a potential energy of 70 J
What is 70 J ?
If the Power an object has triples, then what will happen to its Speed or Velocity?
Speed or Velocity will TRIPLE
True or False?
If speed or velocity is constant during the motion of an object, then it will affect how much Work is done.
(Remember: W = F d)
FALSE
If friction is the only force acting on an object then its KE will ________?
DECREASE
if the Height of an object above the Earth's surface is is cut in half, its potential energy would be _________
cut in half
Energy is changed from one form to another with no net loss or gain is ________ (T or F)
Always TRUE
The "Joule per second" is a measure of _____
What is POWER?