When like atoms are bonded together chemically, they form…
an element
What is the smallest division which can be made in a substance and still retain all the properties of the substance?
A molecule
Water is a _______ because water molecules are composed of two kinds of atoms, hydrogen and oxygen.
Compound
What is any substance whose molecules are composed of unlike atoms?
A compound
When two different elements or compounds are mixed together and the molecules do not combine chemically, the substance is known as a …
Mixture
The state of matter is determined by what two things?
Temperature and pressure
As molecules of solids are heated, their activity or molecular speed is …
Increased
Because there can be no lower temperature than that at which molecular motion ceases, it is called …
Absolute zero
There are two kinds of energy:
Potential energy is due to…
Kinetic energy is due to…
The position of a mass
The motion of a mass
What is the rate at which work is done?
Power
What are the two types of velocity?
Variable and constant.
What is the force or shock which results when the movement of a confined liquid is suddenly arrested or accelerated?
Water hammer
What are the six types of simple machines?
- The lever
- The inclined plane
- The wedge
- The screw
- The wheel and axle
- The pulley
Levers of the third class multiply _______ or _______, rather than force.
Speed, distance
If the wheel is the driving axle, there is a loss in ______ because the driving belt is traveling seven times faster and farther than the driven belt on the axle.
Mechanical advantage of speed
On simple machines it is impossible to gain both _______ and _______ at the same time.
Force, speed
What are the four main functions of a gear system?
- Transmit positive force
- Change direction
- Change speed
- Increase or decrease force
With an odd number of gears in a simple gear train, the driver and driven gears rotate …
In the same direction
Most screw threads are said to have a definite number of…
Threads per inch
The length of the slope of an inclined plane is know as…
The effort distance (ED)
Describe a lever.
A rigid bar which turns around a fixed point.
Describe an inclined plane.
A slanting surface or ramp used to assist the worker in raising objects against the force of gravity.
Describe a wedge.
A tool used to separate or hold.
Describe a screw.
A combination of the principles governing the inclined planes, the wedge, and the wheel and axle into one unit.
Describe the wheel and axle.
A simple machine consisting of a large handle or circular part which is rigidly secured to a smaller part.
Describe a pulley.
A wheel that rigidly fastened to a shaft on which it turns and that transmits motion
What are the different classes of levers?
First Class levers: Fulcrum or pivot is located between the effort and resistance force.
Second Class Levers: Fulcrum is located on one side of both the effort and resistance forces and the resistance force is in the middle .
Third Class Levers: Fulcrum is located on one side of both the effort and resistance forces and the resistance force is at the end.
What are the different classes of a wedge?
Class 1 - Separating Wedge: A wedge used to split material.
Class 2 - Holding Wedge: A wedge used for its holding power.
What are the different categories of a screw?
- To transmit motion
- To apply a tremendous amount of force.
- To hold parts together.
- To obtain measurements.
What are the different classes of the wheel and axle?
Class 1: Transmit force
Class 2: Change in speed
Give an example of a first class lever.
Pliers Crowbar Claw hammer Pickax Wrench Tin snips
Give an example of a second class lever.
Lower control arm
Wheelbarrow
Pedal control
Give an example of a third class lever.
Arm lifting a weight
Fishing pole
Shovel
Give an example of an inclined plane.
Loading dock
Give an example of each of the two types of wedges.
- Separating Wedge:
- Drill Bit Tip
- Knife
- Holding Wedge:
- Door Stop
Give an example of each of the four categories of a screw.
- To transmit motion
- A drive screw to move a carriage on a lathe - To apply a tremendous amount of force
- Screw jack - To hold parts together
- Bolt and Nut - To obtain measurements
- Threaded interns of a caliper
Give an example of each of the two classes of the wheel and axle.
- Transmit force:
- Axle Shaft - Change in speed:
- Step Pulley
- 10 Speed Bicycle
Give an example of a pulley.
Timing belt system
Define energy.
Capacity to do work
Define velocity.
Rate a mass travels in a particular direction.
Acts in accordance with the law of free falling bodies.
Gravity
A force that resists the relative motion or tendency to such motion of two bodies or substances in contact.
Friction
Loss of head at the entrance of a pipe
Turbulence
A closed space at which all air has been removed
Vacuum
What is viscosity?
Resistance to flow.
What is pressure?
Force exerted by a substance on a unit of area.
What is power?
The rate at which work is done.
What is the overcoming of resistance?
Work
What is the rate at which velocity in a mass increases with time?
Acceleration
What is flow rate?
The quantity of a substance that moves past a point in a given time.