Question #593cb

2 Answers
Oct 12, 2015

Force (vecF)(F)is a push or a pull and is measured in Newtons (N)

Impulse (vec I)(I)gives a measure of how long the force acts on the objects and is equal to the change in momentum brought about.
Its units is hence either N.s or kg.m//sN.sorkg.m/s

From Newton's 2nd Law of Motion, the resultant force acting on an objects is equal tot he rate of change of momentum brought about, ie
sum vecF=(dvecp)/(dt)=d/dt(mvecv)F=dpdt=ddt(mv)
Hence vecFdt = vecI = m d vecvFdt=I=mdv

Oct 12, 2015

The impulse gives you the average over time of a rapidly varying force.

Explanation:

Consider a force F(t)F(t) not constant but function of time such as the one experienced by an object (tennis ball) during an impact:
The force varies rapidly between two instants t_1t1 and t_2t2 so that:
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where F_mFm is the mean value of the force so that the grey square area is equal to the red total area under the original curve.