If a ball is thrown into the air with a velocity of 39 ft/s, its height (in feet) after t seconds is given by y = 39t − 16t2. find the velocity when t = 1.
For this case we have the following equation: y = 39t - 16t2 Deriving we have that the speed is given by: v = 39 - 32t Evaluating the speed for t = 1 we have: v = 39 - 32 (1) v = 39 - 32 v = 7 feet / s Answer: the velocity when t = 1 is: v = 7 feet / s
