1. Mass of Ice: If you are investigating how the *shape* of the ice affects melting rate, then the mass of the ice would be a constant. You would use the same amount of ice for each different shape.
2. Temperature of the Surroundings: If you are investigating how the *temperature* of the environment affects the melting rate, then the temperature of the surrounding air or water would be kept constant.
3. Type of Ice: If you are investigating how the *purity* or *type* of ice affects melting rate, you would use the same type of ice throughout the experiment (e.g., pure ice, salt ice, etc.).
4. Surface Area Exposed to Heat: In some experiments, you might want to keep the surface area of the ice exposed to heat constant. This might be relevant if you are investigating the effect of different materials on melting rate (e.g., ice on a metal plate vs. ice on a wooden plate).
5. Heat Source: If you are using a heat source to melt the ice (like a lamp or a hot plate), you would want to keep the heat source and its intensity constant throughout the experiment.
In Summary: The "constant" in your experiment will depend on what factors you are trying to control and what variable you are changing to investigate the melting rate of ice.
