What is the difference in gravitation potential energy when a 3.5 kg box is raised from a height of 1.2m to height of 4.0m?

There are weak or strong attractive forces between atoms of liquids with a high viscosity

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.

If jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy, is being done.