1 Free Body Diagrams a better way. 2 Kentlake Astro-Physics Department 2 Two Ways to Apply Force ...

1

Free Body Diagrams

a better way

Kentlake Astro-Physics Department

22

Two Ways to Apply ForceField Force (W)

Does not involve physical contact between two objects i.e. gravity


33

Two Ways to Apply ForceField Force (W)

Does not involve physical contact between two objects i.e. gravity

Contact Force - physical contact Normal (N) - right angles to the object Friction (f) - parallel to the object Tension (T) - parallel to rope/string


44

Contact Forces

Normal (N) this is applied at

right angles to the surface of the object.

it can be up or down


55

Contact Forces

Normal (N) Friction (f)

Is parallel to the surface on which the object rests.


66

Contact Forces

Normal (N) Friction (f)Tension (T)

is parallel to a rope of string block


77

Name the Forces

Name the force by stating on what by what.

Nb,g

normal force on the box by the ground


88

Draw the FreeBody Diagram

Wb,e

Tb,s


99


Wb,e

Tb,s1

Tb,s2

Tb,s2x

Tb,s2y


1010


Nb,r

fb,r

Wb,eWb,ey

Wb,ex


1111

scale

rope


scale

Wb,e

Nb,s

Wb,e

Nb,sTb,r

b-Bobs-scalee-earth


1212


scale

rope

Wb,e

Nb,sTb,r

b-Bobs-scalee-earth

As you pull on the rope what happens to the scale?

What happens to the forces as the scale reaches zero?How hard is the rope pulling on your hands?


1313


r- rocketg - gasp- pad

Wr,e

Nr,p

Draw the size forces at fueling?

Draw the size of each of the forces at ignition.

fueling ignition

Nr,g Nr,p

Wr,e


1414

FreeBody Diagrams

You learn FreeBody diagrams by doing them.

This is the best and quickest way to learn this technique.

Once the FreeBody diagram is drawn the rest of the calculation is routine.

1 Free Body Diagrams a better way. 2 Kentlake Astro-Physics Department 2 Two Ways to Apply Force ...

Documents

Transcript of 1 Free Body Diagrams a better way. 2 Kentlake Astro-Physics Department 2 Two Ways to Apply Force ...