Characteristics of the movement of a body in many respects depend on the module of initial speed. To find this size, it is necessary to use additional measurements or data. The size of the module of initial speed can be fundamental characteristic, for example, for firearms.
It is required to you
- - roulette;
- - range finder;
- - stop watch;
- - accelerometer;
- - speedometer;
- - angle meter;
- - chronograph.
Instruction
1. At first decide on type of the movement. If it uniform, then is enough to measure length of a way on which the body moved, having made it a roulette, a range finder or other available way and to divide this value for a while for which this movement was carried out. As the movement uniform, the speed module throughout all way will be identical so the received speed will be equal to initial.
2. At the uniformly accelerated rectilinear movement measure by means of the accelerometer acceleration of a body, and by means of a stop watch time of its movement, by a speedometer final speed at the end of a piece of a way. Find value of the module of initial speed, having taken away from final speed performing acceleration for the period of the movement v0=v-a*t. If the value of acceleration is unknown, measure distance which covered a body during t. Make it by means of a roulette or a range finder.
3. Record value of final speed. Find initial speed, having taken away from the doubled value of distance of S divided into time, value of final speed of v, v0=2S/t-v. When it is difficult to measure value of final speed, and acceleration is known, use other formula. For this purpose measure movement of a body and also time which it was in way. From value of movement take away performing acceleration on time square divided into 2, and divide result into time, v0= (S-at²/2) / t or v0=S/t-at/2.
4. When the body begins the movement at an angle to the horizon, it is influenced by gravity. To find the module of initial speed, by means of the angle meter measure a corner to the horizon under which the body begins to move. By means of a roulette or a range finder measure distance at which the body will fall to the Earth's surface. To define the module of initial speed, divide distance of S into a sine of the doubled corner α. Take a square root, v0= from the received result √ (S/sin(2α)).
5. To measure the module of initial speed of the bullet which is released from small arms use a chronograph. For this purpose establish it as it is specified in its instruction as chronographs happen different types. After that make a shot of weapon, on a board of a chronograph the result will appear. Shoot several times and take average value of indications of a chronograph. It will also be the module of initial speed of a bullet, the small arms released from this type.