What happens when two forces act in the same direction

Rank the torques on the five doors shown in the figure above from least to greatest. note that the magnitude of all the forces is the same

Abeam of electrons with of wavelength of 7.5 x 10-6 m is incident on a pair of narrow rectangular slits separated by 0.75 mm. the resulting interference pattern is projected onto a screen 10.0 m from the slits. what is the separation of the interference maxima in the resulting interference pattern?

Zeros that follow non-zeros numbers and are also to the right of a decimal point are significant