A student is viewing a specimen under the microscope at a total magnification of 400x. If the oculars of the microscope are 10x, what is the magnification of the objective lens in use

Four potential forces can act on the ball. which combination of forces will keep the ball in static equilibrium? the length of the arrows represents the magnitude of the force.

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.

What object a collides with object b and bounces back its final momentum is?