A lens is formed from a plastic material that has an index of refraction of 1.59 . If the radius of curvature of one surface is 1.15 m and the radius of curvature of the other surface is 1.80 m , use the lensmaker's equation to calculate the magnitude of the focal length | f | and the power | P | of the lens.

a longitudinal wave moves energy that is to the direction of the wave’s movement. - true

the answer would be   dignified - apex

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form