Understanding Mechanical Work and Power in Physics
Understanding Mechanical Work and Power
Labor demands activity, class, or effort of either muscular or intellectual origin. The concept of work is used in a narrower sense.
Mechanical Work
When a force acts along its own line of action, this concept implies two necessary conditions:
- A) Defeated force
- B) Displacement along the line of action
There will be no mechanical work when either of these two factors is zero.
How do these factors influence mechanical work?
It becomes obvious when lifting a heavier body that more work will be done. Also, if this body is to be lifted to a greater height, therefore, the work done to overcome a force is directly proportional to the defeated force and displacement.
The applied force is not always in the direction of displacement. Suppose a body moves horizontally under the action of a force that forms an angle with the direction of displacement. The force is composed of two components: F1, in the direction perpendicular to the displacement, and F2, which tends to drag the body horizontally and vertically. F2 is canceled by the body’s weight; only F1 does work.
The mechanical work done by a force to move a body is obtained by multiplying the displacement by the component of force in the direction of displacement.
Joule
The work done by a 1N force to move its point of application 1m in the same direction and sense as the force.
Wh (Watt-hour)
The work done in 1 hour by a 1-watt engine.
kWh (Kilowatt-hour)
The work done in 1 hour by a 1-kilowatt engine.
Power
In the definition of work, the concept of time is not included. In practice, work is done through machines or engines that are characterized by the greater or lesser amount of work they can develop in a given time. That is their power.
Power is the work a machine or engine is capable of performing per unit of time.
Watt
The power of a machine that can do the work of 1 joule every second.
- 1 kW = 1000 W
- 1 CV = 735 W
- 1 HP = 744 W
Understanding Mechanical Work and Power
Labor demands activity, class, or effort of either muscular or intellectual origin. The concept of work is used in a narrower sense.
Mechanical Work
At the expiration of a force along its own line of action, this concept involves two conditions necessary for as:
- A) Defeated force
- B) Displacement along the line of action
There will be no mechanical work when either of these two factors is zero.
How do these factors influence mechanical work?
It becomes obvious when lifting a heavier body that more work will be done. Also, if this body is to be lifted to a greater height, therefore, the work done to overcome a force is directly proportional to the defeated force and displacement.
The applied force is not always in the direction of displacement. Suppose a body moves horizontally under the action of a force that forms an angle with the direction of displacement. The force is composed of two components: F1, in the direction perpendicular to the displacement, and F2, which tends to drag the body horizontally and vertically. F2 is canceled by the body’s weight; only F1 does work.
The mechanical work done by a force to move a body is obtained by multiplying the displacement by the component of force in the direction of displacement.
Joule
The work done by a 1N force to move its point of application 1m in the same direction and sense as the force.
Wh (Watt-hour)
The work done in 1 hour by a 1-watt engine.
kWh (Kilowatt-hour)
The work done in 1 hour by a 1-kilowatt engine.
Power
In the definition of work, the concept of time is not included. In practice, work is done through machines or engines that are characterized by the greater or lesser amount of work they can develop in a given time. That is their power.
Power is the work a machine or engine is capable of performing per unit of time.
Watt
The power of a machine that can do the work of 1 joule in one second.
- 1 kW = 1000 W
- 1 CV = 735 W
- 1 HP = 744 W