Page 7-2
At this point, we need only press
K
twice to store these variables.
To solve, first change CAS mode to
Exact
, then, list the contents of A2 and A1,
in that order:
@@@A2@@@
@@@A1@@@
.
Use command SOLVE at this point (from the S.SLV menu:
„Î
) After
about 40 seconds, maybe more, you get as result a list:
{ ‘t = (x-x0)/(COS(
θ
0)*v0)’
‘y0 = (2*COS(
θ
0)^2*v0^2*y+(g*x^2(2*x0*g+2*SIN(
θ
0))*COS(
θ
0)*v0^2)*x+
(x0^2*g+2*SIN(
θ
0)*COS(
θ
0)*v0^2*x0)))/(2*COS(
θ
0)^2*v0^2)’]}
Press
µ
to remove the vector from the list, then use command OBJ
, to get
the equations listed separately in the stack.
Note
: This method worked fine in this example because the unknowns t and
y0 were algebraic terms in the equations. This method would not work for
solving for
θ
0, since
θ
0 belongs to a transcendental term.
Example 2 – Stresses in a thick wall cylinder
Consider a thick-wall cylinder for inner and outer radius
a
and
b
, respectively,
subject to an inner pressure
P
i
and outer pressure
P
o
. At any radial distance
r
from the cylinder’s axis the normal stresses in the radial and transverse
directions,
σ
rr
and
σ
θθ
, respectively, are given by
,
)
(
)
(
2
2
2
2
2
2
2
2
2
a
b
r
P
P
b
a
a
b
P
b
P
a
o
i
o
i
−
⋅
−
⋅
⋅
+
−
⋅
−
⋅
=
θθ
σ
.
)
(
)
(
2
2
2
2
2
2
2
2
2
a
b
r
P
P
b
a
a
b
P
b
P
a
o
i
o
i
rr
−
⋅
−
⋅
⋅
−
−
⋅
−
⋅
=
σ