Power
Function of power
A function of power has following three kinds.
- I change the form of the object.
- I support an object.
- I change a state of the motion of object.
There is the kind of the power in various ways, but shows below representative power.
- Power that the gravity (weight) … earth goes mainly on an object and goes down
- The power that the spring which lengthened elasticity … and the bounce that I narrowed are going to come back to the cause
- The plane where an object of …2 frictional force touches and power to work to disturb the exercise of object between aspects
- Power that a magnetic force … magnet attracts iron and pays between magnets and the power that I reject
- Power to pull against each other by power to rub electric power … objects together, and to occur and the power that I avoid
Of the power express; one
The unit to express size of Newton (N) … power. 1N is equal to gravitational size to act on an object of 100g.
Three elements … point of action (the point where power acts on) of the power, a direction of the power, volume of power. Function of power is hit in these three elements.
Of the power express it, and, using one … arrow, express three elements of the power. In the point of the beginning of the arrow, in the direction of the arrow, the length of the arrow expresses volume of power in a point of action in a direction of the power.
※The gravitational point of action assumes it the center of the object like the chart below basically and expresses it downward.
Growth of power and the spring
The growth of the Hooke’s law … spring is proportional to volume of power to attract bounce.
※The definition is like that, but is all right when I solve a problem even if I think that the growth of the spring is proportional to the mass of an object hung to a spring.
The length of the spring in the state to hang nothing to a natural long … spring.
What cm lengthens when I hang an object of 600g for bounce to be prolonged for 3cm when I hang an object of 1:200 g of example?
A: Because power to act on a spring becomes triple 6N from 2N, the growth of the spring becomes triple 9cm.
The length of the spring became 15cm when I hung an object of 2:200 g of example, and the length of the spring became 21cm when I hung an object of 600g. What cm is the natural head of this spring?
A: Because I grow by 6cm by increase in 400g, I grow by 3cm at 200 g. Thus, it becomes 12cm at 15cm – 3cm.
Weight and mass
Gravitational size to act on a weight (gravity) … object. The weight changes by a place to measure. (weight = gravity)
※In comparison with the earth the month gravity about
Quantity of the mass … object itself. The mass does not change by a place to measure.
An example: The object of 60 kg is a month, but mass is 60 kg on the earth. In addition, the object of 600N is a month, and gravity becomes 100N on the earth.
| The earth | Month | |
| Mass | 60 kg | 60 kg |
| Weight (gravity) | 600N | 100N |
⇐3.It is pressure and atmospheric pressure sound 5⇒