Can someone explain this one to me

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?

On average a herd of elephants travels 10 miles in 12 hours you can use that information to answer different questions drag each expression to show which is answers

Find the missing dimension extra points