Solar Pool Heater

Question

A pool owner is building a solar heater to keep her pool a comfortable 85°F. So far, she has a design that consists of piece of wood with black drip irrigation tubing coiled around and secured. This part of the design is shown in the picture.

The pool owner is making a few choices in the design of the solar heater. She is deciding whether to leave the wood plain or paint it, either white or black. She wants to choose the option that will help the solar heater warm the pool quickest. To make her decision, she cuts three pieces of wood that are one foot by one foot. Then, she paints one of them white and one of them black. She leaves the third piece of wood its original color. She places the three pieces of wood into the sunlight for 30 minutes and records their temperatures every five minutes. The table shows this data.

Wood Color Temperatures (in °F)
0 minutes 5 minutes 10 minutes 15 minutes 20 minutes 30 minutes
Plain Wood 75 75 76 76 77 77
White Paint 75 75 75 75 76 76
Black Paint 75 76 78 80 81 82
The second decision the pool owner would like to make is whether she should use 100 feet of drip irrigation tubing or 200 feet of drip irrigation tubing. She would also like to connect the design to a small programming device that will turn the water pump for the pool on and off based on the pool's temperature. When the pump is on, water will be pumped out of the pool and through the black tubing. Then, the water will flow back into the pool as it exits the tubing. When the pump is off, no water will be pumped out of the pool and through the black tubing. The pool owner needs to decide how to program the device so that the temperature of the pool is as close to 85°F as possible.

Two-Part Question
Multiple Choice Question
The following question has two parts. First, answer Part A. Then, answer Part B.

Part A:

After the pool owner finalizes her design, she runs the solar heater. The graph shows the data she collects during a 24-hour period.

Use the data to identify how the design has failed.

A.
The solar heater

Answer 1

It appears that your message was cut off, and I don't have access to the specific graph you're referring to regarding the solar heater's 24-hour data. However, I can help reason through potential design failures based on the information given about the initial experiment with wood and the heating behavior of the solar heater.

Here are some potential choices that could indicate failure in the solar heater's performance based on the understanding of solar heating principles:

A. The solar heater did not sufficiently heat the water in the pool to reach the desired temperature of 85°F over the 24-hour period.

B. The temperature of the water flowing through the black tubing did not increase significantly compared to the ambient temperature, indicating inadequate heat absorption.

C. The pump’s timing or operation may not have been correctly programmed to optimize the heating effect based on the fluctuations in pool temperature.

D. The surface area of the tubing may have been insufficient to absorb enough solar energy if the water was not heated adequately despite being pumped through the black tubing.

E. The ambient conditions, like cloud cover or temperature variations throughout the day, might not have been taken into account, affecting the heater’s overall efficiency.

To provide a conclusive answer, I would need to analyze the data you mentioned in the graph. If possible, please provide information about the collected temperatures or any patterns observed in the performance over the 24-hour period.