Number 21 please help me solve it thank youu

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?

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

Afair survey question is one that does not encourage biased responses. which survey question is fair? a.) do you agree that only unethical people take credit for other people’s work? b.) have you ever taken credit for somebody else’s work? c.) have you ever engaged in unethical behavior, such as taking credit for somebody else’s work? d.) don’t you think it is unethical to take credit for somebody else’s work?