A rocket is projected directly upward with an initial velocity of 352 ft/sec from the ground. After t seconds, it's height in feet is given by f(t) = -16t^2 + 352t. After how many seconds will it be 640 feet above the ground?

Right triangle lmn has vertices l(7, –3), m(7, –8), and n(10, –8). the triangle is translated on the coordinate plane so the coordinates of l’ are (–1, 8). (x, y) → (x + 6, y – 5) (x, y) → (x – 6, y + 5) (x, y) → (x + 8, y – 11) (x, y) → (x – 8, y + 11)