energy conservation Flashcards
Power equations
P =W/t
P=Fd/t
P= Fv
define power
power is defined as the rate at which work is done or the rate at which energy is transferred or converted.
measured in W or j
What is the correct unit for mechanical energy?
J
1J=1nm of force
work is?
Work is W = F.d. If the force
Work is done when a force moves an object through a distance.
It is a measure of the energy transfer that occurs when an object is moved due to the application of force along a displacement
what is moment of interia
work equation
W=FD
what is Moment of Inertia?
Newtons 2nd law states that an object at rest will undergo acceleration if an a force is applied.
moment of inertia
linear= f=ma pushing bicycle easy pushing a truck immovable so by definition it is the relationship between mas and its state of rest.
what is a moment
The turning effect produced by a force. Calculated as the product of
SI—newton meters (N * m)
These units have the same dimensions as those
for work.
bones are__________
act as Levers that Lever
A lever is a system that tends to change the mechanical advantage of a applied force.
It consists of two forces and a fulcrum
or hinge. Pivot point .
The two forces are called an
-effort force (such as a muscular force)
-resisting force (such as a weight held in the hand or a
ground reaction force). The perpendicular distance of each force from the fulcrum is called the lever arm.
what acts as the fulcrum?
Joints act as fulcrums
A fulcrum is a point or support on which a lever pivots
the rotation or the radius of rotation occurs around the fixed point of the joint where the moment arm moves through an angular distance.
Joints = fulcrum
Bones = levers
Muscles are the force mechanism that angular motion or torque
formulae related to the turning effect?
T = Fd┴
ta) (tau) is the torque,
r is the distance from the axis of rotation, and
F is the force applied.
What is a rotary force that produces angular acceleration?
how does torque relate to force produced?
Torque
longer the lever the greater torque less force
shorter the lever less torque less force required ore force
think of hinge closer to fulcrum and a spanner that is long
We are concerned with two types of mechanical energy:
- Kinetic energy (KE)
That component of the mechanical energy of a body resulting from
its motion. Two forms of kinetic energy are identified.
Kinetic energy of translation = 1⁄2m∙v - Potential Energy (PE)
That component of the mechanical energy of a body resulting from its position.
what is hooks law ?
strain or Elastic energy
*A form of potential energy
*Potential to be converted to kinetic energy
Hooke’s Law:
PE = ½kx2
*Force is required to bend/stretch a spring
*More force (F) = more stretch (x)
* F = kx
*More bend = more energy stored
or
Hooke’s Law is a principle in physics that states the force needed to extend or compress a spring by some distance is proportional to that distance.
