30n of force is used to raise a box that weight 60n up an incline plane. what is the mechanical advantage of the incline plane?

Which is a substance that can be separated by physical means and is not the same throughout

How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57×10−21 newtons?

Find an expression for the electric field e⃗ at the center of the semicircle. hint: a small piece of arc length δs spans a small angle δθ=δs /r, where r is the radius. express your answer in terms of the variables q, l, unit vectors i^, j^, and appropriate constants.