Page:Model steam turbines; how to design and build them (IA modelsteamturbin00harrrich).pdf/16

12 and the increase or change of momentum

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The change of momentum in (11) as the result of the blow is termed an impulse, and the action of a constant force may be regarded as an indefinitely large number of impulses gradually changing the momentum of the body.

If the force which we call F acts for t seconds, then


 * Ft=$W/g$(v₂-v₁),

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Where the initial velocity is zero, the whole change of velocity is V feet per second, and (12)=Ft==$W/g$V, and if t, the time of application of the force, is unity,

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