CAASPP Grade 11 Math - Performance Task

Last updated about 1 month ago
6 questions

Lights, Candles, Action!

Your friend Abbie is making a movie. She is filming a fancy dinner scene and she has two types of candles on the table. She wants to determine how long the candles will last.

She takes a picture, lights the candles, and then lets them burn for 1 hour. She then takes a second picture. You can assume that each candle burns at the its own constant rate.


Candle Type A Initial height = 20 cm
Candle Type B Initial height = 10 cm

Candle Type A height after burning for 1 hour = 16 cm
Candle Type B height after burning for 1 hour = 9 cm

You will use this information to help Abbie think about the candles she might use for her film.
Required
1
Candles A and B are lit at the same time. What will be the height, in cm, of each candle after 3 hours of burning?
Candle Type A: _______
Candle Type B: _______
Required
2

Candles of each type were lit at the same time. Abbie thinks that since Candle Type A burns more quickly than Candle Type B, that it will burn out (have a height of 0 cm) first.

Julie thinks that since Candle Type B starts out much shorter than Candle Type A, it will be the candle to burn out first.

Which candle will burn out first? Give a mathematical explanation to convince Abbie and Julie of your solution. Clearly identify the quantities involved.

Required
2

Abbie has 3 hours left to film. She lights a new Candle Type A and Candle Type B and then starts filming.

In the 3 hours she has left, will Abbie capture the moment when the candles are exactly the same height?

Explain to Abbie how you can determine the answer.

Required
2

You have decided to use functions to help Abbie think about the candles.

You show her how to represent the height of a candle, h, as a function of time, t, using this equation:
h = k + nt

First, explain to Abbie what k and n represent in order to model the different candles. Be specific in your explanation.

Required
1

Now, choose either Candle A or Candle B to create an equation that will tell Abbie the height of the candle at t hours after it is lit.

Determine what the numerical values for k and n should be for the candle you chose.

Using these k and n values, write an equation that tells Abbie the height h of the candle, in cm, at t hours after it is lit.

Required
1
For her next film, Abbie wants candles that will burn for exactly 8 hours. You want to give her a choice by designing two different candles (Type C and Type D).

Using the equation h = k + nt, determine two different pairs of values for k and n that will meet the requirement to burn down to a height of 0 cm in exactly 8 hours.

Fill in the blanks to complete the table to show two possible sets of values for k and n for your new candle designs.


Candle Type C (k) _______
Candle Type C (n) _______

Candle Type D (k) _______
Candle Type D (n) _______