Ch 10: Force, Work, Power Flashcards
What is the def of force?
That which pushes or pulls through the force of gravity to alter the motion of an object.
Internal and external causes of force?
internal: muscles
external: gravity, other objects, friction
Force equation
force = mass x accel
Must produce a greater what in order to lift something?
must produce a greater force than gravity
A vector has what three things?
magnitude
direction
point of application
a change in magnitude means what?
force applied
a chance in the point of application means what?
where the force is being applied
ex: pushing instead of pulling
Momentum equation
momentum = mass x velocity
newton’s law of reaction
for every action, there is an equal and opposite reaction
what is the def of work?
when force is overcome for a given distance
work equation
work = force x displacement
difference between positive and negative work
positive force: same direction as movement (concentric)
negative force: opposite direction as movement (eccentric)
power definition
the rate at which work is done
power equation
power = work / time
-or-
power = force x displacement / time
-or-
power = force x velocity
velocity equation
displacement / time
-or-
velocity = power / force
