If a certain cannon is fired from a height of 8.2 meters above the ground, at a certain angle, the height of the cannonball above the ground, h, in meters, at time, t, in seconds, is found by the function h(t)=−4.9t^2+27.5t+8.2. Find the time it takes for the cannonball to strike the ground. The cannonball will strike the ground after about ___ seconds