In science one year, we did a test of dropping a water bottle from different heights over a Pringle, and we had to protect the Pringle with a paper. But how would increasing the height increase the force is the mass and acceleration is the same?
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I had the same question when learning F = ma.
In this case, the force you are concerned with isn’t gravity, but the force of the Pringle/paper trying to *stop* the water bottle – in other words, accelerate it from its current velocity to 0 in a *very* short amount of time. A water bottle moving faster requires even more acceleration to slow it to 0, and thus the Pringle/paper needs to apply more force. By Newton’s first law, that same force also gets applied to the Pringle/paper.
Materials and devices that help safely stop a fall tend to work by being easy to deform (think a foamy pad or something), which basically allows the object to continue moving for a bit longer rather than stop all at once. This increase in the time to stop means a lower acceleration and thus a lower force imparted on both objects. From an energy perspective, some of the energy of the falling object gets transferred into the deformation of the foamy material instead of the (possible) deformation/breaking of the falling object.
The acceleration due to gravity doesn’t change with height, nor does the force imparted by gravity on the object, so your intuition is correct there.
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