You will find force of the draft setting a body in motion, having calculated the vector sum of all forces operating on a body. At uniform motion on a horizontal surface force of draft compensates forces of resistance to the movement. In case the body moves on the inclined plane, it should overcome also gravity - when calculating consider it.
It is required to you
- dynamometer, scales, table of coefficients of friction, accelerometer.
Instruction
1. Direct measurement of force of draft Put a body on a surface on which you will move it. Attach to it a dynamometer and begin to move with a constant speed, take readings of a dynamometer in newtons - it is and there will be a value of force of draft.
2. Measurement of force of the draft operating on rectilinearly moving tel that case if the body moves on the horizontal site of a way, learn materials of which the body and a surface is made. In the table of coefficients of friction for different materials, pick up the necessary combination and the coefficient corresponding to it. By means of scales or any other way measure the mass of the moving body. Measure acceleration with which the body the accelerometer moves or calculate it if speeds at the beginning and the end of a way and its length or time of passing are known. To find draft force, increase friction coefficient by 9.81 (acceleration of gravity), add value of acceleration to result, and increase the turned-out number by body weight (F=m • (μ\• 9.81+a)). If the body moves evenly, acceleration will be equal to zero.
3. In case the body moves on the inclined plane, measure a corner of its inclination. To find draft force in case the body climbs it, you will increase friction coefficient by 9.81 and a cosine of the angle of an inclination of the plane to the horizon, to this number add work 9.81 on a sine of this corner, to the received result add acceleration. Increase the received number by the body weight which needs to be measured F=m in advance • (μ\• 9.81•Cos(α) +9.81 ·Sin(α) +a). At free fall of a body force of draft is served by gravity. To find it, it is necessary to increase body weight by acceleration of gravity (9.81): F=m•9.81.