Which cup will keep a hot drink warm longer, Paper,Plastic, Styrofoam, or Glass?

We will look into the science behind thermal insulation and see which cup keeps hot drink warm longer. In this experiment principle of thermal conductivity applies. We will take hot water and check its temperature in different cups over time.
Ajeet Singh
Grade 5

Hypothesis

Based on my research, I think styrofoam will keep the hot drink warm longer because it has lower thermal conductivity so the speed of heat transfer will be slow.

Research

Heat can transfer in 3 different ways -

  • Thermal conductivity

  • Thermal convection

  • Radiation

 

Thermal conductivity happens when heat moves from a source at a higher temperature (liquid) to a source at a lower temperature (cup) until temperature becomes equal. Thermal conductivity of a material determines how good an insulator it is. Materials that are not good at conducting heat are called insulators. So the best materials for insulation  are the ones  with the lowest thermal conductivity. While some materials are better than others at conducting heat. Materials that are good at conducting heat are called conductors. To keep the liquid warmer, heat transfer needs to be reduced. To lower the speed of heat transfer, a good thermal insulator is needed. In this experiment we will try to determine which material insulates heat the best.

 

Key Words

  • Insulator- An insulator is a material that doesn’t easily allow heat to pass through it.

  • Thermal conductivity- Thermal conductivity of a material determines how good an insulator it is. It is the ability of a material to conduct/transfer heat.

  • Temperature- It is the measure of hotness or coldness measured in terms of Fahrenheit or Celsius.

Variables

Controlled (constant) variable

  • Starting temperature

  • Amount of water

  • Time

 

Manipulated (test) variable

  • Different cup material

 

Responding Variable

  • Change in temperature in each cup at different time intervals

 

 

Procedure

  1. Gather all materials

  2. Boil water in a pan up to 196 F

  3. Line up all the cups and pour 150ml into each cup using a measuring cup

  4. Measure the temperature of each cup after every 30 seconds until 300 seconds

  5. Repeat experiment 2 more times using the same amount of water (150 ml) and starting with the same water temperature.

Observations

 

Temperature (Fahrenheit)   TRIAL 1

Time (sec)

Styrofoam

Paper

Plastic

Glass

0

196

196

196

196

30

187

187

177

167

60

179

176

168

163

90

173

169

160

150

120

167

163

154

151

150

163

157

150

144

180

158

154

145

139

210

155

149

140

136

240

151

146

136

132

270

148

143

133

132

300

145

140

129

126

 

Temperature (Fahrenheit) TRIAL 2

Time (sec)

Styrofoam

Paper

Plastic

Glass

0

196

196

196

196

30

183

174

170

165

60

177

168

160

160

90

170

162

159

155

120

165

158

154

150

150

161

154

146

140

180

158

150

143

139

210

153

147

138

137

240

150

143

135

129

270

147

140

132

125

300

144

137

130

122

 

Temperature (Fahrenheit)TRIAL 3

Time (sec)

Styrofoam

Paper

Plastic

Glass

0

196

196

196

196

30

181

178

177

165

60

175

172

161

159

90

169

167

153

152

120

164

160

150

146

150

159

157

143

141

180

155

153

139

137

210

152

150

135

133

240

149

147

134

132

270

146

143

131

129

300

142

139

129

125

Analysis

Three trials were performed and in each trial temperature readings were taken at 30 seconds intervals up to 300 seconds. Styrofoam always showed the highest temperature amongst all 4 different cups. In the end, average of temperature reading at each interval for every cup was taken. 

 

 

 

 

Conclusion

So as per the three trials, Styrofoam keeps the hot liquid warmer for longer time. Followed by paper and then plastic. Glass doesn’t fare well as compared to other cups and recorded the lowest temperature at the end of each trial. So, Styrofoam is the best cup in keeping hot liquid warmer for longer time.

 

 

Application

I was intrigued as to why cafe’s use paper cups and if there are other better alternatives. So I chose the topic ‘Which cup will keep a hot drink warm longer: paper, plastic, styrofoam, or glass?’ In this experiment it was found that Styrofoam keeps the hot liquid warmer for longer time. 

So this raised another question, that why aren’t the cafe’s using styrofoam instead. Then I did some further research and found that styrofoam is more harmful to the environment. Also, heat can cause chemicals to release from the foam and into the food. Repeated use of these cups can be a health risk. 

So Styrofoam even though keeps hot drink warmer, it's use should be very limited. Example, you can use it in cold months if you are outdoors.

 

 

Sources Of Error

INSTRUMENTAL ERROR:

- Thermometer reading

-TImer reading

-Wrong measurement due to miscalibration.

ENVIRONMENTAL ERROR:

- Different room temperature for diff trials

HUMAN ERROR

-Input wrong readings in the table.

-Read wrong data from equipments.

PROCEDURAL ERROR:

-Use of different procedure for different trials.

 

Acknowledgement

I would like to express my gratitude to my teacher Mrs. Parhar and Khalsa School Calgary for providing me their support , guidance and environment to learn and grow.

I am grateful to my parents for their motivation and encouragement given to me in completing this project.

Finally, I would like to thank CYSF for providing us the platform to show our project work and exchange knowledge.