Introduction to mechanical power transmissions for millwright students.

1. Mechanical Power
Transmission

2. •Mechanical advantage is the ratio between
the output force and input force. It is also
the ratio between the input distance and the
output distance.
•MA = output force/input force.
•MA = input distance/output distance.
•A compound machine is a machine that
combines two or more simple machines.

3. •Force: Forces can be described as a push or pull
on an object .
•They can be due to phenomena such as gravity,
magnetism, or anything that might cause a mass
to accelerate .
•In physics, a force is any interaction that, when
unopposed, will change the motion of an object.
•Newton's first law says that an object will remain
at rest or will continue to move in a straight line
unless it is acted on by a net force.

4. • Energy: Energy is the ability to do work.
• Energy comes in different forms:
* Heat (thermal) * Light (radiant) * Motion (kinetic)
* Electrical * Chemical * Nuclear energy *Gravitational
• People use energy for everything from walking to
sending astronauts into space.
• There are two types of energy:
• Stored (potential) energy
• Working (kinetic) energy
• For example, the food a person eats contains chemical
energy, and a person's body stores this energy until he
or she uses it as kinetic energy during work or play.

5. • Mechanical energy is the sum of kinetic and potential energy in an object that is
used to do work. In other words, it is energy in an object due to its motion or
position, or both.
• There are two forms of mechanical energy: potential energy and kinetic energy.
1. Potential energy is the stored energy of position due to the vertical position of
an object within Earth's gravitational field and is calculated using the equation:
PEgrav = m•g•h
• where m is the mass of the object (with standard units of kilograms), g is the
acceleration of gravity (9.8 m/s/s) and h is the height of the object (with standard
units of meters) above some arbitrarily defined zero level (such as the ground or
the top of a lab table in a physics room).
2. Kinetic energy is defined as the energy possessed by an object due to its motion.
The equation for kinetic energy is:
KE = 0.5 • m • v2
• where m is the mass of the object (with standard units of kilograms) and v is the
speed of the object (with standard units of m/s).
• The total mechanical energy possessed by an object is the sum of its kinetic and
potential energies.

6. •Work: Work results when a force acts upon an
object to cause a displacement (or a motion) or,
in some instances, to hinder a motion.
•Power is the rate at which work is performed.
•Power transmission is defined as the transfer of
energy from its place of generation or storage
to a location where it does work.
•Example: Electrical energy is stored in a
battery; it is then transmitted through wires to
a motor where it is converted into mechanical
energy to do work.