PLZZZZ HELP ME ASAP!!!!!!!!!!!!!!!!!!

a catapult launches a boulder with an upward velocity of 148 ft/s. the height of the boulder,h, in feet after t seconds is given by the function h=-16t^2+148t+30. what is the boulder's maximum height? how long does it take to reach it's maximum height? round to the nearest hundredth, if necessary.