·does a change in the initial speed change the time of flight? If so, how?

Explanation:

When an object is thrown at an angle θ with the horizontal . It covers the parabolic path . We can calculate the  time of flight by the relation

T =

here u is the initial velocity and g is acceleration due to gravity .

and T is time of flight .

Thus if we increase the initial velocity , the time of flight also increases and vice versa .

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

conservation of mass

mass before something happens = mass afterwards