Impulse of a body call the work of body weight on its speed. To find measurement of this size learn how the weight and speed of a body after its interaction with other body changed. Change of an impulse of a body can be found, using one of types of record of the second law of Newton.
It is required to you
- Scales, radar, dynamometer
Instruction
1. Find the mass of a moving body and measure the speed of its movement. After its interaction with other body, at the studied body the speed will change. In this case from final speed (after interaction) take away initial speed and increase a difference by body weight Δp=m ∙ (v2-v1). Measure instantaneous velocity by the radar, body weight - scales. If after interaction the body began to move aside, opposite to that, the code moved before interaction, then final speed will be negative. If change impulse positive – it grew if negative – decreased.
2. As force is the reason of change of speed of any body, it also is the reason of change of an impulse. To calculate change of an impulse of any body, it is enough to find an impulse of force operating on this body for some time. By means of a dynamometer measure force which forces a body to change speed, giving it acceleration. Along with the help of a stop watch measure time which this force affected a body. If force forces a body to move quicker, then consider it positive if slows down its movement – consider it negative. Force impulse equal to change of an impulse will be equal to the work of force for the period of its action Δp=F ∙Δt.
3. If in interaction of bodies no external forces, then on law of conservation of momentum act on them, the sum of impulses of bodies before interaction remains identical in spite of the fact that impulses of separate bodies can change. For example, if as a result of a shot from a gun the bullet weighing 10 g received the speed of 500 m/s, then its change of an impulse will be Δp=0.01 kg ∙ (500 m/s-0 m/s) =5 kg ∙ m/s.
4. According to law of conservation of momentum, change of an impulse of a gun will be the same, as well as at a bullet, but opposite in the direction as it after a shot will move opposite aside that where the bullet will take off.