If you shine a laser on two slits with a separation of 0.185 mm, and the angle of second order maximum is 0.188 degrees, what is the wavelength of the laser light?

i cant see the choices man

spectral lines lyman is one set

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards