Fisica

UNIVERSIDAD NACIONAL
“PEDRO RUIZ GALLO”

FACULTAD DE INGENIERÍA AGRÍCOLA

EJERCICIOS DE FISICA

CURSO : Física General

DOCENTE :Ing. Jaime Abanto Castillo

ALUMNOS : Cabrera Vasquez, Luis Alex

Carranza Olivera, Wilmer

Diaz Cabrera, JoseCarlos

Huaman Vilchez, Jose Wilmer

Mirez Solorza, Oscar

Lambayeque, Marzo del 2011

GRUPO DE EJERCICIOS Nº 7

1. Calcular elproducto vectorial de:

[pic] = 2.12[pic]+ 8.15[pic] - 4.28 [pic]

[pic] = 2.29[pic] - 8.93[pic] - 10.5[pic]

Solución:

[pic] X [pic]= ( 2.12[pic]+8.15[pic] - 4.28 [pic] ) X ( 2.29[pic] - 8.93[pic] - 10.5[pic] )

[pic] [pic] [pic]

[pic] X [pic]= 2.12 8.15 -4.28

2.29-8.93 -10.5

[pic] X [pic]= [pic][ (8.15)(-10.5) – (-4.28)(-8.93)] + [pic][ (-4.28)(2.29) - (2.12)(-10.5)] +

[pic][ (2.12)(-8.93) - (8.15)(2.29)]

[pic] X[pic]= [pic][ -85.575 – 38.2204 ] + [pic][ -9.8012 + 22.26 ] + [pic][ -18.9316 – 18.6635 ]

[pic] X [pic]= -123.7954 [pic] + 12.4588 [pic] - 37.5951 [pic]

[pic] X [pic]= -124[pic] + 12.5[pic] -37.6 [pic]

2.- Hallar la derivada respecto al tiempo de:

[pic] = x [pic]+ 2y [pic] - z² [pic]

Solución:

[pic]=[pic][pic]= [pic][pic]

3.- si: [pic] = 2t[pic]+ 3t²[pic] - t[pic] y [pic] =t[pic]+t²[pic] +t³[pic], demostrar que:

[pic](P.Q)= 4t + 8t³ , comprobar el resultado, aplicando :[pic].Q + P. [pic]=[pic](P.Q)

Solución:

[pic](2t[pic]+ 3t²[pic] - t[pic]).(t[pic]+t²[pic] +t³[pic]) + (2t[pic]+ 3t²[pic] - t[pic]).[pic](t[pic]+t²[pic]+t³[pic])

[pic](P.Q)=(2[pic]+ 6t [pic]-...