A 20 kg cart on wheels has been pushed up against a wall with a spring (k = 244 N/m) between the wall and the cart. If the spring is compressed a distance of 0.1m and a force of 20 N is continued to be applied toward the wall, what will the acceleration of the object be?

Unpolarized light of intensity i_0=750w/m^2 is incident upon two polarizers. after passing through both polarizers the intensity is i_2=280w/m^2. (a) what is the intensity of the light after it passes through the first polarizer in w/m^2? (b) write an equation for the angle between the polarizers in terms of the initial (i_0) and final (i_2) intensities. (c) find the angle between the polarizers in degrees.