Question

While taking a photograph on a balcony, you drop your cell phone. The function y=-162²+400 represents the height y (n

feet) of the phone t seconds after it is dropped. After how many seconds does the phone land on the ground?

Time:____seconds

Answer 1

1.5713484 seconds.

Explanation:

We can assume the full function as:

`y = -162t^2+400`

Since we want to find time when the phone hits the ground, y should be 0.

`0 = -162t^2 + 400`

Now, we can solve for t:

1) Move 400 to the left side:

`-400 = -162t^2`

2) Divide both side by -162:

`(-400)/(-162) = t^2`

3) Find the square root of both sides:

`\sqrt{(-400)/(-162)} = t`

4) This means that:

t = 1.5713484 seconds