what two objects would not work for an experiment that is mass and measure how long they take to fall?
Two objects that would not work for such an experiment are a feather and a floating balloon.
The feather is very light and has a large surface area, which causes it to experience a lot of air resistance. As a result, it falls slowly and the time it takes to reach the ground would not accurately represent its mass.
Similarly, a floating balloon is also affected by air resistance, which makes it rise instead of falling. It would not provide reliable measurements of mass and time during free fall.