quarter 2 - q2 Flashcards
When there is a change in motion, there is ____.
work
work is a scalar quantity
true or false
true
Result of a force acting upon an object to cause a displacement of the object; when you move in place, then there is no ______ done.
work
work formula
w=fd
In order for a force to qualify as having _____ done on an object, there must be a displacement and the force must be the cause of that displacement.
work
- Only the force that acts on the direction of motion counts towards work
true or false
true
- this formula only applies if F and d are parallel (same direction)
w = fd
formula If force and
displacement do
not point in the
same direction
W=Fd (cos)
TYPES OF WORK (3)
WORK AGAINST INERTIA
WORK AGAINST FRICTION
WORK AGAINST GRAVITY
Applying force to cause change in motion
E.g. throwing/kicking a ball
Work against inertia
Involves height
W = mgh
m = mass
g = acceleration due to gravity
Work against gravity
Work in going up and going down will always be equal no matter how slow or how quick the person moved
TRUE OR FALSE
TRUE
Ability to do work.
Expressed in Joules
ENERGY
No energy means no work is done.
TRUE OR FALSE
TRUE
: property of a body or system of bodies by which work can be done or performed.
Energy
The _____ possessed by a body is equal to the total work it can do
energy
ENERGY IS A SCALAR QUANTITY
T OR F
TRUE
The energy of objects at rest; stored energy
Potential energy
Energy stored in elastic materials such as rubber bands, bungee cords, springs, arrows drawn into a bow
Elastic potential energy
The result of stretching or compressing
The more the object is stretched/compressed, the more stored energy is evident in the object.
Elastic potential energy
stored as the result of the gravitational attraction of the Earth for the object
Gravitational potential energy
is directly proportional to both mass and height.
GPE
The energy of objects in motion
Once the object at rest starts moving, the PE it has will then be converted to _____
Kinetic Energy
Rate at which work is done
Rate at which energy is expended from PE to KE and KE back to PE
POWER
is the amount of work done divided by the time it takes to do it
Power
is the energy expended/transformed divided by the time it takes to expend it.
Power
T OR F
Work has nothing to do with the amount of time the force acts to cause the displacement
TRUE
No matter how fast or slow you do a task, it does not affect POWER but it effects WORK
TRUE OR FALSE
FALSE
No matter how fast or slow you do a task, it does not affect work but it effects power
Time is inversely proportional to power. Therefore, the shorter the time the work is done, the higher the power exerted. The longer the time, the lesser the power exerted.
TRUE
TRUE
