Question | Answer |
There are ______________ classifications for the different typers of levers. | Three |
The location of the lever fulcrum in relation to the load and applied fore determines the _________________ of levers. | Classification |
A lever which has the fulcrum between the applied force and the load is called a ___________-____________ lever. | First-class |
A lever with the fulcrum located at the end of the bar can have either a __________-_________ lever of a ____________-_____________ lever. | Two; second-class; third class |
When using a first-class lever, the amount of weight or force and the _______________ fromthe fulcrum can be varied according to the need. | Distance |
In order to have a balanced state with a first-class lever, the___________ on one side of the fulcrum times the distance from the ____________ on that side must equal the ____________ on the other side multiplied by its__________ from the fulcrum. | weight; fulcrum; weight; distance |
if a maintenance mechanic desires to lift a 200 pound generator off the ground using a lever as the lifting device, he must place a fulcrum under the lever, If a fulcrum is placed three feet from the end of the liver lifting the generator, and the leveris | 120 pounds; exactly 120 pounds would only balance the lever |
Second-class levers always have the load attached between the ___________ and the __________. | Fulcrum; applied force |
Second-class levers are normally employed to provide a mechanical _____________ when attempting to lift a load. | advantage |
After attaching a load to a second-class lever, you find you have sufficient force to lift the load, but cannot raise the load high enough to get a dolly under it. To correct this situation, you should move the load____________ toward the __________. | Outward: applied force |
After attaching a load to a second-class lever, you find you have sufficient force to lift the load, but cannot raise the load high enough to get a dolly under it. To correct this situation, you should move the load____________ toward the __________. | Outward: applied force |
If a load weighing three pounds is attached on inch from the fulcrum of a six-inch second-class lever, how much force is required to lift the weight? | 0.5 pounds (3x1 = 3 and 0.5 x 6 = 3) |
The applied force of a third-class lever can never be __________ than the force exerted by the load itself. | less |
Third-class levers provide a mechanical advantage in that they can vary the __________ and ___________ that a load moves. | speed; distance |
The greater the distance between the applied force and the fulcrum, the ___________ speed of movement the load will have. | less |
The closer the applied force is to the fulcrum of a third-class lever, the ___________ the distance in travel of the load. | Greater |
The steering Wheel of an automobile is a good example of a ______________ or _________-__________-___________ machine. | Crank; wheel and axle |
The wheel-and-axle machine works much on the same principle as that of a _____________. | Lever |
Torque is determined in a simple wheel-and-axle machine by Multiplying the __________ ______________ times the ______________ from the center of rotation. | radius; axle |
gears can be used to ________ or ________ force, increase or decrease _______________, or change the _____________ or motion. | magnify; reduce; speed; direction |
When a force is applied to the smaller of two gears, the resultant output speed will be _____________. | decreased |
Dividing the number of teeth on the driver gear by the number of teeth on the driven gear will determine the multiplier for computing an increase of decrease in ______________. | speed |
Dividing the number of teeth on the driven gear by the number of teeth on the driver gear will determine the multiplier for computing an increase or decrease in ___________________. | Touque or force |
A particular gear arrangement that provides for a reduction in speed of applied force will have the effect of _____________ the amount of force applied. | increasing |
A gear arrangement that provides for an increase between input and output force will also have the effect of ___________ the speed of the applied force. | Decreasing |
Gears (do/do not) _________ need to be of different sizes to cause an increase of decrease in speed and / or force. | do |
Gears (do/do not) __________ need to be of the same size to cause a change in direction of applied force. | Do not |
An inclined plane is primarily used to reduce the force necessary to ___________ or ___________ a weighted object. | Raise; lower |
If a ramp is six times as ling as it is high, the mechanical advantage of using the ramp is _______________, | six |
Computer the force necessary to roll a barrel weighing 500 pounds up a 15 foot inclined plane to a height of 6 feet. How much force is necessary? | 200 pounds ( 500 x 6 = 3000 and 3000 divided by 15 = 200 |
To multiply the length of a jack handle by 2 x 3.14, you are determining the radius of a jack handle are, You can use this figure to determine the ______ _______ of the jack by further dividing this product of 2 P;R by the pitch of the jack screw. | Mechanical advantage |
Determine the lifting capabililty of a screw jack that has a 100-pound force applied to a 36-inch jack handle. Assume the screw pitch of the jack to be 1/8 inch. Also assume that the construction of the jack is such that it will not collapse under the str | approximately 30.4 tons (2x 3.14 x 36 divided by 1\8 (or .125) = 1808.64 x 100 divided by 2000=90.4 approximately |