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Robin wanted to shove a rubber pipe up a plastic tap. The problem is that the pipe's diameter is smaller than that required to secure a tight fit. So, Robin switched on a hair dryer and pointed it towards the pipe. He found that now the pipe fitted in easily. Why is this so?

Correct answer: A. The rubber pipe expanded when heated, allowing it to fit over the tap

  • A. The rubber pipe expanded when heated, allowing it to fit over the tap
  • B. The plastic tap deformed due to the heat from the hair dryer
  • C. Heat caused a chemical reaction leading to adhesion between the rubber and plastic
  • D. None of the above options are correct

Explanation

The correct answer is that the rubber pipe expanded due to the heat from the hair dryer. The increase in temperature caused the molecules within the rubber to gain kinetic energy and move more vigorously, leading to an expansion of the material. This expansion made the pipe more pliable and allowed it to fit over the plastic tap, despite its initially smaller diameter. Other options, such as the deformation of the tap or adhesion caused by heat, do not accurately explain the observed phenomenon. The key concept here is the thermal expansion of materials when heated.

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About Thermal Equilibrium and Heat

Thermal equilibrium means that bodies in contact have the same temperature and no net heat flows between them. The topic distinguishes heat from temperature, uses the zeroth law of thermodynamics, and covers heat transfer, specific heat capacity, thermal expansion and the conditions for reaching equilibrium.

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