Can someone please help me with this

After t seconds, a ball tossed in the air from the ground level reaches a height of h feet given by the equation h = 144t-16t^2. after how many seconds will the ball hit the ground before rebounding?

Eden has a part time job. she is paid ? 7.20 an hour the week she worked 18 and a half hours how much is she paid

Need plz been trying to do it for a long time and still haven’t succeeded