40 miles per hour to feet per second rounded to the nearest whole number

Aball is thrown from a height of 139 feet with an initial downward velocity of 15 ft/s. the ball's height h (in feet) after t seconds is given by the following. h=139-15t-16t^2 how long after the ball is thrown does it hit the ground? round your answer(s) to the nearest hundredth. (if there is more than one answer, use the "or" button.) t =

Simplify. (-2)^-3 a. -8 b. -1/8 c. 1/8 d. 8

How do you find the circumfrance of a circle?