Julie's class is testing their egg protection contraption by dropping them off the roof at their school.

The functionh(t)=−16t^2+40

is representative of the situation, where t
𝑡
is time in seconds and h

is height in feet.

Part A: Graph this function. Link to Desmos calculator

Part B: Which point represents the height of the school roof? (Write your answer as an ordered pair)

Part C: What is the height of the egg at t=0.5
𝑡
=
0.5
second? The height of the egg at 0.5 seconds is feet.

Part C: What is the height of the egg at t=1
𝑡
=
1
second? The height of the egg at 1 second is feet.

Part D: When does the egg hit the ground? The egg hits the ground at seconds. (Round your answe

1 answer

To solve the problem step-by-step:

Part A: Graph the function

To graph the function \( h(t) = -16t^2 + 40 \) using the Desmos calculator, go to Desmos and enter the equation. This will give you a parabola that opens downward since the coefficient of \( t^2 \) is negative.

Part B: Height of the school roof

To find the height of the school roof, we need to evaluate the function at \( t = 0 \) because this represents the initial height, or the height of the roof before the egg starts to fall.

\[ h(0) = -16(0)^2 + 40 = 40 \]

Thus, the point representing the height of the school roof is:

Ordered pair: \( (0, 40) \)

Part C: Height of the egg at \( t = 0.5 \) seconds

Now we calculate the height when \( t = 0.5 \):

\[ h(0.5) = -16(0.5)^2 + 40 \] \[ h(0.5) = -16(0.25) + 40 \] \[ h(0.5) = -4 + 40 = 36 \]

Therefore, the height of the egg at \( t = 0.5 \) seconds is 36 feet.

Part D: Height of the egg at \( t = 1 \) second

Now we calculate the height at \( t = 1 \):

\[ h(1) = -16(1)^2 + 40 \] \[ h(1) = -16 + 40 = 24 \]

Thus, the height of the egg at \( t = 1 \) second is 24 feet.

Part E: When does the egg hit the ground?

To find out when the egg hits the ground, we need to set \( h(t) = 0 \):

\[ -16t^2 + 40 = 0 \] \[ 16t^2 = 40 \] \[ t^2 = \frac{40}{16} = 2.5 \] \[ t = \sqrt{2.5} \approx 1.58 \]

Therefore, the egg hits the ground at approximately 1.58 seconds (rounded to two decimal places).

Summary of Answers

  • Part B: (0, 40)
  • Part C (0.5 seconds): 36 feet
  • Part D (1 second): 24 feet
  • Part E: 1.58 seconds