Chapter 14
What is wedge?
A V-shaped object whose sides are two inclined planes sloped toward each other.
What is compound machine?
A combination of two or more simple machines that operate together.
What is ideal mechanical advantage?
A machine is the mechanical advantage in the absence of friction.
What is mechanical advantage?
A machine is the number times that the machine increases an input force.
What is lever?
A rigid bar that is free to move around a fixed point.
What is pulley?
A simple machine that consist of a rope that fits into a groove in a wheel.
What is wheel and axle?
A simple machine that consists of two disks or cylinders, each one with a different radius.
What is inclined plane?
A slanted surface along which a force moves an object to a different elevation.
What is the equation for actual mechanical advantage?
Actual mechanical advantage = Output force/Input force
How does the actual mechanical advantage of a machine compare to its ideal mechanical advantage?
Actual mechanical advantage is the equals the ratio of the output force to the input force, while ideal mechanical advantage is a mechanical advantage in the absence of friction.
What is machine?
An apparatus using or applying mechanical power and having several parts, each with a definite function and together performing a particular task.
What is screw?
An inclined plane wrapped around a cylinder.
How can you increase the work output of a machine?
By how far the work output and output distance are from one another.
What is the equation for efficiency?
Efficiency = Work output/Work input X 100%
When does a force do work?
For circular motion, the centripetal force always acts at right angles to the motion. It changes the direction of the motion, but it does no work on the object. This can be applied to any circular orbit.
What conditions must exist in order for a force to do work on an object.
Force must act in the same direction the object moves.
Why is the efficiency of a machine always less than 100 percent?
Friction
What is the equation for ideal mechanical advantage?
Ideal mechanical advantage = Input distance/Output distance
What is output distance?
In machines that increase distance instead of force.
What is input force?
Is the initial force used to get a machine to begin working.
What is work output?
Is the work done by a simple machine.
How do machines make work easier?
Machines make the time go faster.
What formula relates work and power?
Power is the rate of doing work.
What is watt?
SI unit of power.
What is work input?
Simple machines is always less than the energy input, even though the forces may be drastically different.
What is input distance?
That is, a small input force can accomplish a task requiring a large output force.
What is efficiency?
The % of the work input that becomes work output.
What is joule?
The SI unit of work.
What is input arm?
The distance between the input force and the fulcrum.
What is output arm?
The distance between the output force and the fulcrum.
What is horsepower?
The equal to about 746 watts.
What is fulcrum?
The fixed point the bar rotates around.
How can two machines appear identical and yet not have the same actual mechanical advantage?
The measuring the actual forces acting on the objects may be different.
What is work?
The product of force and distance.
What is power?
The rate of doing work.
What is actual mechanical advantage?
The ratio of the output force to the input force.
How does the work on a machine compare to the work done by a machine?
They both deal with having to use products to make something by something else.
What are the equation for work and power?
Work = Force X Distance Power = Work/Time
How are work and power related?
Work done is a measure of the energy transferred when a force moves a load,power is the rate of energy transfer.
How are work input and work output related for a machine?
Work input is is work done on a machine equal to the effort force times the distance through which the force is applied. While work output is the work done by a simple machine.