Here's why:
* Thermal energy is directly related to the change in potential energy. When an object falls, its gravitational potential energy is converted into kinetic energy, and ultimately into thermal energy (due to friction and air resistance). The higher the object falls, the greater the change in potential energy, and therefore, the greater the amount of thermal energy produced.
* Mass is a key factor in potential energy. The formula for potential energy is:
* PE = mgh
Where:
* PE = potential energy
* m = mass
* g = acceleration due to gravity
* h = height (falling distance)
* Keeping the falling distance constant hides the relationship between mass and thermal energy. If you keep 'h' constant, any change in thermal energy will only be due to changes in the 'm' (mass) term. This will give you a direct relationship between mass and thermal energy, but only if you ignore the influence of the falling distance.
Instead of keeping the falling distance constant, you should:
* Vary the mass of the object. Use different masses for your experiment.
* Measure the change in temperature. This will directly indicate the change in thermal energy.
* Analyze the relationship between the change in temperature and the mass. You should find that a greater mass will result in a greater temperature change (assuming the same falling distance).
In conclusion:
Keeping the falling distance constant would obscure the true relationship between mass and thermal energy. By varying the mass and measuring the temperature change, you can accurately demonstrate how thermal energy is affected by the object's mass.
