A mechanical advantage less than ' 1 ' means the output <u>force</u> is less than the input
force. But <em>distance</em> is gained ... the load moves farther than the driving force moves.
An example of all this is a big father and his little 4-year-old daughter playing
on the see-saw in the park. He adjusts the board so that he's much closer
to the pivot than she is, and that way, their weights can balance each other.
It's set up so that the mechanical advantage from him to her is less than ' 1 '.
Now, look at what happens when Dad sits down on his end of the see-saw,
and pushes it down with his 180 pounds of force. At the other end, the board
is barely lifting her with a force of just 30 pounds. BUT ... as he sinks down
only 1 foot against his end of the board, <em>her</em> end rises 6 feet off the ground.
True, because for example you are on a bus and you want to know if you are moving or not so you look at a house which doesn't move and stays stationary.
Answer:
what is the question? there isn't one
Save money on fuel and go for longer
Answer:
To correct the defects of vision by measuring the radius of curvature and thus the power of the lenses.
Explanation:
A spherometer is an instrument used to measure the curvature of objects such as lenses and curved mirrors.
Generally it consists of a fine screw which is moving in a nut carried on the center of a 3 small legged table or frame. The feet forms the vertices of an equilateral triangle. The lower end of the screw and those of the table legs are finely tapered and terminate in hemispheres.
If the screw has two turns of the thread to the milli meter the head is generally divided into 50 equal parts, so that differences of 0.01 millimeter may be measured without using a vernier scale.
The spherometer is used to measure the radius of curvature of the lenses so that the opthalmologist find the focal length of the lens and then give the power to the lens to correct the defects of vision.
