195k views
0 votes
A small toy rocket is launched from a 48-foot pad. The height (h, in feet) of the rocket t seconds after

taking off is given by the formula h = - 3t2 +0t + 48. How long will it take the rocket to hit the
ground?
t =

2 Answers

6 votes

Answer:

4 seconds.

Explanation:

When the rocket hits the ground, its height will be 0. Therefore, since we are given an expression for the height of the rocket dependent on the time, we can simply set it equal to 0 and solve for the time and find how long the rocket will take to hit the ground. I'm assuming the equation is
h = -3t^(2) + 48

Now set this equal to 0


0 = -3t^2+48. Solve for t by isolating it.


-48 = -3t^2


16 = t^2

From here, by taking the square root, we see that t is either equal to 4 or -4 in seconds. Since we can't have negative time, we can clearly see that the answer is 4 seconds.

Hope this helps

User Sam Ellis
by
8.9k points
2 votes

Okay, here are the steps to solve this problem:

1) The height (h) of the rocket t seconds after launch is given as: h = - 3t2 + 0t + 48

2) We want to find the time (t) when the rocket hits the ground (h = 0)

3) Set the formula equal to 0: - 3t2 + 0t + 48 = 0

4) Factor the left side: - 3(t2 - 0t) + 48 = 0

5) Solve for t2 - 0t: t2 - 0t = 16

6) Add 0t to both sides: t2 = 16 + 0t

7) Take the square root of both sides: t = 4

Therefore, the time for the rocket to hit the ground is 4 seconds.

So in this case, t = 4

Let me know if you have any other questions!

User Paul Lockwood
by
8.3k points