Special forces:
1 Normal Force
:
label
(force from a support surface)
Size : depend on press force (weight) of object.
No motion in to the surface. ( No smash)
N
r
2 Tension:
force from a rope/string. Label
size : varies
T, Quantity without a vector hat is only size of it.
Direction: along rope, always pointing away from
object.
Tension inside massless rope in all location has the
same size.
T
r
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
and steps
1 identify and isolate the object of interest
2 identify all forces on the objects
acted by
other objects (why can you pull your hair
and leave the ground).
.
3 pick x – y axis. ( based on acceleration
direction for convenience)
4 break up all forces into xy components
5 F
net x
= m a
x
,
F
net y
= m a
y
(x,y independent)
6 solve for any two unknowns
( from the above two equations)
(Again Math skills here. )
In most cases either a
x
or a
y
is zero, if you
choose the right x and y directions.
(Or both are zero when the object stay rest
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '09
 JamesM.Lockhart
 Physics, Force, Normal Force, apparent weight

Click to edit the document details