1.2.E.sagews

from sympy.physics.units import *
from sympy import *

print("------ User input ---------------------")

symbolic = True
symbolic = False

if symbolic:
    # quantity = symbol:
    F = var("F")
else:
    # quantity =  factor times unit:
    F = 2 * newton

s2 = sqrt(2)
s6 = sqrt(6)

e1 = Matrix([ 1, 0,-1 ])/s2
e2 = Matrix([ 1, 2,-1 ])/s6
e3 = Matrix([-1, 2,-1 ])/s6
Fv = Matrix([ 0, 0,-F ])
Nv = Matrix([ 0, 0, 0 ])

# Variables:
S1, S2, S3 =var('S1, S2, S3')
eq = Eq(S1*e1 + S2*e2 + S3*e3 + Fv, Nv)
pprint(eq)

unknowns = [S1, S2, S3]

sol = solve(eq, unknowns)
pprint(sol)
for x in sol:
    S = sol[x]
    pprint(N(S,2))

------ User input --------------------- [ ___ ___ ___ ] [ \/ 2 *S1 \/ 6 *S2 \/ 6 *S3 ] [ -------- + -------- - -------- ] = [0] [ 2 6 6 ] [ ] [ ] [0] [ ___ ___ ] [ ] [ \/ 6 *S2 \/ 6 *S3 ] [0] [ -------- + -------- ] [ 3 3 ] [ ] [ ___ ___ ___ ] [ \/ 2 *S1 \/ 6 *S2 \/ 6 *S3 2*kg*m] [- -------- - -------- - -------- - ------] [ 2 6 6 2 ] [ s ] ___ ___ ___ -2*\/ 2 *kg*m \/ 6 *kg*m -\/ 6 *kg*m {S1: --------------, S2: ----------, S3: ------------} 2 2 2 s s s -2.8*kg*m ---------- 2 s 2.4*kg*m -------- 2 s -2.4*kg*m ---------- 2 s