It took 1.35 minutes for a rock thrown horizontally out of a plane to hit the ground . How high was the plane ?

The time required for initially horizontal projectile motion to occur is the same as the time required for the object to fall to its final height. Thus, a ball thrown horizontally will reach the ground at the same time as a ball dropped from the same height.

Explanation:

presidency should be the title

the correct answer is:   "   3.6 % " .

          →   the unemployment rate is:   " 3.6 % " .

explanation:

to calculate the "unemployment rate" :

the "unemployment rate"   =

  [# of people unemployed] /   [working age population]   * 100 %   ;

                =   [9 million] / [250 million]     *   100 % ;

    →     note:   the units of "million" cancel out;

                    since:   " {million} / {million} = 1 " ;

                =   (9 / 250)   * 100 %   ;

                = 0.036 * 100 % ;

                =   3.6 %

answer:   the unemployment rate is:   " 3.6 % " .