One is the magic number
If MA is greater than 1: Less effort
force & Greater effort distance
If MA is less than 1: Greater effort
force & Less effort distance
𝑰𝑴𝑨 =
𝑫𝑬
𝑫𝑹
𝑨𝑴𝑨 =
POE Unit 1 Exam Study Sheet
Ohm’s Law
𝑽=𝑰∗𝑹
𝑭𝑹
𝑭𝑬
Electric
Power
𝑷=𝑰∗𝑽
2nd Class Levers:
1st Class Levers:
Work
3rd Class Levers:
Moment - M=d x F
Torque- τ = d x F
𝐀𝐌𝐀
𝐏𝐨𝐮𝐭
% 𝐄𝐟𝐟𝐢𝐜𝐢𝐞𝐧𝐜𝐲 = 𝛈 =
∗ 𝟏𝟎𝟎 =
∗ 𝟏𝟎𝟎
𝐈𝐌𝐀
𝐏𝐢𝐧
Wheel & Axel: A wheel
is a lever arm that is
fixed to a shaft, which
is called an axle. The
wheel and axle move
together as a simple
lever to lift or to move an item by rolling. It is
important to know within the wheel and axle
system which is applying the effort and
resistance force – the wheel or the axle.
IMA=4
Pulley
Fixed - Changes the
direction of force
Moveable- Force
directions stay
constant
Pulley IMA = #
strands opposing
the load
Circumference 2  π  r
IMA =
=
Pitch
P
𝐏=
Mech Power
𝟏
𝐓𝐡𝐫𝐞𝐚𝐝𝐬 𝐩𝐞𝐫 𝐢𝐧𝐜𝐡
𝑷=
𝑾
𝒕
Energy- Ability to do work
Potential Energy- Capacity to do work
Kinetic Energy- Energy which a body possesses because of
its motion
Conservation of Energy- Energy cannot be created or
destroyed, but it can change from one form to another.
Electrical Power- Electrical energy does work
Mech Power- Mechanical energy does work
Fluid Power -Energy transferred by liquids and gases
Thermodynamics- The study of the effects of work, heat
flow, and energy on a system
Thermal Energy is kinetic energy in transit from one
object to another due to temperature difference.
Thermal equilibrium- is obtained when touching objects
within a system reach the same temperature.
𝐏𝐧𝐞𝐭 = 𝛔𝐀𝐞(𝐓𝟐 𝟒 − 𝐓𝟏 𝟒 )
R- Value: Thermal Resistance of a
Material
U- Value: Coefficient
of Heat Conductivity
𝟏
𝐔
𝑼=
𝑹𝑻 = 𝑹𝟏 + 𝑹𝟐 + 𝑹𝟑
𝐏=
𝐐
𝚫𝐓
𝐏=
𝐤∗𝐀∗𝚫𝐓
𝐋
𝑷
𝑨𝜟𝑻
k=
𝐏∗𝐋
𝐀∗𝚫𝐓
DR
𝐐 = 𝐦 ∗ 𝐜 ∗ 𝚫𝐓
Compound Machines:
𝐌𝐀 𝐓 = 𝐌𝐀 𝟏 ∗ 𝐌𝐀 𝟐 ∗ 𝐌𝐀𝟑
𝐆𝐑 𝐓 = 𝐆𝐑 𝟏 ∗ 𝐆𝐑 𝟐 ∗ 𝐆𝐑 𝟑
Convection: The transfer of thermal energy
by movement of fluid (liquid or gas)
Conduction: The transfer of thermal energy
within an object or between objects from
molecule to molecule
Radiation: The process by
which energy is transmitted
n = # of teeth
through
medium, including empty
d= diameter a
w = ang vel
space, as electromagnetic
t = torque
waves
𝐈𝐌𝐀 =
𝐋(𝐬𝐥𝐨𝐩𝐞)
𝐇
𝑰𝑴𝑨 =
𝑫𝑬 𝑳
=
𝑫𝑹 𝑯
𝑮𝑹 𝒏𝒐𝒖𝒕 𝒅𝒐𝒖𝒕 𝝉𝒐𝒖𝒕
𝝎𝒊𝒏
=
=
=
=
𝟏
𝒏𝒊𝒏
𝒅𝒊𝒏
𝝉𝒊𝒏
𝝎𝒐𝒖𝒕
𝑭𝒐𝒖𝒕 = 𝑴𝑨 ∗ 𝑭𝒊𝒏
Characteristics of a series circuit
𝐕𝐓 = 𝐕𝟏 + 𝐕𝟐 + 𝐕𝟑
𝐈𝐓 = 𝐈𝟏 = 𝐈𝟐 = 𝐈𝟑
𝐑𝐓 = 𝐑𝟏 + 𝐑𝟐 + 𝐑𝟑
Stefan’s Law: All objects lose and gain thermal energy by
electromagnetic radiation.
𝐑=
DE
W = F · d║
Energy: The ability to do work
Energy sources are defined as
– Nonrenewable: Sources that cannot
be replaced once used (Fossil Fuels,
Coal, Oil, Natural Gas, Uranium:
Nuclear energy (fission)
– Renewable: Sources that can be
replaced once used (Animals, Food,
Biomass, Biofuel (Ethanol, Methanol)
– Inexhaustible (Hydroelectric, Tidal,
Geothermal, Wind, Solar)
– Ways to Store Energy: Hydrogen &
Batteries
– Alternative Energy: Any fuel that is
not identified as a fossil fuel
Characteristics of a Parallel circuit
𝐕𝐓 = 𝐕𝟏 = 𝐕𝟐 = 𝐕𝟑
𝐈𝐓 = 𝐈𝟏 + 𝐈𝟐 + 𝐈𝟑
𝟏
𝐑𝐓 =
𝟏
𝟏
𝟏
𝐑𝟏 + 𝐑𝟐 + 𝐑𝟑
0th Law: If two systems are separately
found to be in thermal equilibrium with a
third system, the first two systems are in
thermal equilibrium with each other.
1st Law: Thermal energy can change form
and location, but it cannot be created or
destroyed.
2nd Law: Thermal energy flows from hot
to cold
Entropy- is the measure of how evenly
distributed heat is within a system.