If an object of mass 70kg falls from a height of 500 m, what is the maximum velocity of the object?

H = 1/2 * g * t^2     since initial velocity is zero

v = g * t    where v is the final velocity

t = v / g

H = 1/2 g * v^2 / g^2 = 1/2 v^2 / g

v = (2 * H * g)^1.2

v = (2 * 500 * 9.8)^1/2 = 99 m/s

Check: t = v / g = 99 / 9.8 = 10.1 sec

H = 1/2 * 9.8 * 10.1^2 = 500 m

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