math help!!! i need help! please explain?

Question

For problems 11 through 13, a projectile is fired upward with an initial speed of 800 feet per second. It is given that

h=-16t^2+800
(h= height of the ball)

11. factor the equation
a. h=t(-16t+800)
b. h=(-16t)(t-50)
c. h=(-16)(t^2+50t)

i put a as my answer but i dont know if it is right.

12. What will you set h equal to in the equation to find how many seconds it takes for the projectile to hit the ground?

a. h=0
b. h=1

13. Use your graphing calculator to find how many seconds before the projectile hits the ground. Let y1=.16t^2+800t , or factor and solve for t algebraically.

a. 0 seconds
b. 50 seconds

please explain this to me. i am not very good with word problems. i would really REALLY REALLY appreciate it!

thank you!

:]

Answer 1

Hello

11. The equation is -16t^2 + 500t so we have to take out a -16t giving us -16t(t -50) or answer b

12. we set it equal to 0 as h = the height above ground. So a is the answer here

13. So here we use our factored equation -16t(t-50) and set it = 0 so -16t = 0 or t-50 = 0 so the answer is b 50 seconds

Hope This Helps!!

Answer 2

for 11) it's b
for 12) it's a
for 13) it's b

Answer 3

wont help with your homework

Answer 4

what grade are you in