Un bloque de 3Kg de masa es empujado contra una pared mediante una fuerza P que forma un
ángulo de Ѳ=50° con la horizontal, como se muestra en la figura. El coeficiente de fricción estático
entre el bloque y la pared es de 0,25. Determine el valor de la fuerza P que permite al bloque
permanecer fijo

Light from two different sources are incident upon the same side of a polarizing filter. light from one source is polarized with total intensity ip, while light from the other source is unpolarized with total intensity iu. as you rotate the polarizing filter through 360 degrees, the intensity of the transmitted light on the other side varies by a factor of 9. what is the relative intensity of the initial polarized source to the unpolarized source, or ip/iu?