Question

Mark for Review
2 A plece of paper was dropped from the top of a tall building. The height of the plece of paper above the
ground can be found using the function y = -2.5x + 30, where x is the time in seconds the plece of paper
has been in the air.
11
20
15
10
5
17 18 2017 2016
-10
-15
-30
How many seconds did It take the plece of paper to reach the ground?
Record your answer and fill in the bubbles on your answer document.

Answer 1

Answer:

12 seconds

Step-by-step explanation:

Given

$y = -2.5x + 30$

Required

Determine the time taken to reach the ground

For the paper to reach the ground, y = 0

So, we have:

$y = -2.5x + 30$

$0 = -2.5x + 30$

Collect Like Terms

$2.5x +0 = 30$

$2.5x = 30$

Divide through by 2.5

$2.5x/2.5 = 30/2.5$

$x = 30/2.5$

$x = 12$

Hence:

Time taken is 12 seconds