External force and momentum change for an object (7-23)

Question 1 of 3

Question

The sum of all external forces acting on an object

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Question

Change in momentum $\vec{p}$ of the object during that time interval

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Review

We learned in Section 7-3 that if external forces act on a system of objects for a time $\Delta{t}$ , the result is a change in the momentum of the system from an initial value $\vec{P}_i$ to a final value $\vec{P}_f$ . This change is given by Equation 7-13: $\left(\sum{\vec{F}_\mathrm{external\ on\ object}}\right) \Delta{t} = \vec{P}_f - \vec{P}_i$

Now suppose the system is made up of only a single object. Then we can replace the symbol $\vec{P}$ (for the momentum of a system) by $\vec{p}$ (for the momentum of a single object), and Equation 7-13 becomes: