The concept of an impulse was entered into physics by the French scientist René Descartes. Descartes called this size not an impulse, but "the number of the movement". The term "impulse" appeared later. The physical quantity equal to the work of body weight on its speed is called a body impulse: Ó =. Only moving bodies possess an impulse. Impulse unit in the international system of units is kilogramm*metr in a second (1kg*m/c). For an impulse the fundamental law of the nature called law of conservation of momentum is fair.
Instruction
1. For calculation of required size, it is necessary to bring units of measure of two sizes entering a formula into accord. One of these sizes defining a body impulse – weight. Weight – a measure of inertness of a body. The more body weight, the is more difficult to change the speed of this body. For example, the case having weight of 500 kg is more difficult to get moving forward, than a case weighing 100 kg. And it is obvious, resistance of the first case to force trying to change its speed more than at the second. Weight is measured in kilograms (in the International System of Units). If weight is given not in kilograms, then it is necessary to translate it. The following measurements of this size meet: tons, grams, milligrams, centners, etc. Example: 6 t =6000kg, 350 g =0.35kg.
2. Other size on which the impulse depends directly – speed. If the body is based (speed is equal to zero), then the impulse is equal to zero. At increase in speed the impulse of a body increases. An impulse – size vector, having the direction which coincides with the direction of a vector of speed of a body. Measure speed in meters per second (1m/c). When finding an impulse the speed should be transferred to m/s in case its measurement is given in km/h. To transfer to m/s it is necessary to increase numerical value of speed by one thousand and to divide into three thousand six hundred. Example: 54km/h =54*1000/3600=15м/с.
3. So, to define an impulse of a body two sizes are multiplied: weight and speed. Ó =. Example 1. It is necessary to find an impulse of the running person, weighing 60 kg. He runs with a speed of 6 km/h. Decision: at first speed is transferred to m/s. 6 km/h =6*1000/3600=1.7 m/s. Further according to a formula, r =60kg*1.7m/with =100 kg*m / page. Example 2. To find an impulse of the based car weighing 6 t. Such problem can be not solved. The impulse of not moving body is equal to zero.