Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies. molten iron has a density of 7.0g/cm cubed. in its solid state, iron has a density of 8.0g/cm cubed.

As we know that mass of the iron will remain same in solid state as well as in molten state as per mass conservation theory

Now we can say

since mass is the product of volume and density so we can say

now from above equation we have

now by solving above equation we have

so final volume after it get solidify will become 175 cm^3

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

ill do it for 100, also this isnt 80 its 40