- #1

JJBladester

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## Homework Statement

I'm taking a test next week on kinetics and energy of moving particles. Problems include things like sliding blocks, friction, braking automobiles, collars sliding on poles, springs, max/min heights/velocities, tensions, accelerations, etc...

We learned two ways of solving problems in the kinetics realm...

__Newton's second law and energy equations__.

**When do I use one vs. the other?**

## Homework Equations

__Newton's 2nd Law__

F=ma

PE=Potential Energy, KE=Kinetic Energy, SE=Spring Energy, Work could be from friction, drag, etc.

__Energy Eqn__

PE

_{1}+KE

_{1}+SE

_{1}+Work=PE

_{2}+KE

_{2}+SE

_{2}

## The Attempt at a Solution

My gut says that if the problem is asking for an acceleration or a normal force, F=ma needs to get involved. Otherwise, I may or may not need to use F=ma + the energy eqn.

We're using chapter 12/13 in Vector Mechanics for Engineers by Beer/Johnston 8th Ed.