Length of a body, piece or trajectory of the movement can be found, having measured it, having calculated by means of mathematical formulas or in parameters of the motion of bodies overcoming distance which length is measured. In all cases length is recognized by the technique.
It is required to you
- - ruler;
- - roulette;
- - laser range finder;
- - roller range finder.
Instruction
1. For measurement of length of a piece use a ruler. Apply it to the measured piece and having combined one of its ends in zero. Determine distance at which there is other end of a piece by a scale of a ruler. It will also be its length. Measure pieces of the bigger size by means of a roulette in the same way. Measure length by a laser range finder, having sent a beam from the initial point to final, and on the screen length of the measured piece will be highlighted at once.
2. To measure length of a subject or the line which is not a straight line use a roulette. She has to repeat completely all bends of the line which length is measured. If there is such opportunity, for measurement of length of an indirect trajectory use a roller range finder (curvimeter). Put its wheel in the initial point of a trajectory, and carry out by it to a final point. On a special scale or a board there will be a distance passed by a wheel.
3. Length of all parties of a geometrical figure is called perimeter. To find it measure each of the parties of a figure, and find their sum. For some figures the perimeter can be found on formulas: • to find perimeter of an equilateral triangle, measure its party and increase by 3; • for a square and a rhombus increase length of the party by 4; • for a parallelogram, including a rectangle increase the sum of the unequal parties by 2; • for a rectangular triangle to the sum of legs, add a hypotenuse which is equal to a root square of the sum of squares of legs.
4. To find circle length, increase its radius by number 6.28, or diameter on number 3.14.
5. To learn length of a way which there passed S body, its average speed of v on this way increase by time which was required on its overcoming t (S=v∙t). In the same way count a way of a body at uniform motion. If the body moves uniformly accelerated, with an initial speed of v0 and acceleration of a during t time, then learn length of a way, having found the sum of the work of initial speed for time and half of acceleration for a while in S square = V0 • t+a • t²/2. When calculating consider that if the body slows down, then acceleration has the sign "minus".