The formula you mentioned, a = 2d/t^2, is not the correct formula for acceleration. The correct formula for acceleration is given by:
a = (vf - vi) / t
where a is the acceleration, vf is the final velocity, vi is the initial velocity, and t is the time taken.
In your case, since you dropped the ball from a height of 1 meter, the initial velocity, vi, is 0 m/s because the ball starts from rest. The final velocity, vf, can be determined using the equation for free fall:
vf = vi + gt
where g is the acceleration due to gravity (approximately 9.8 m/s^2) and t is the time taken. Plugging in the values, we have:
vf = 0 + (9.8 m/s^2)(0.32 s) = 3.136 m/s
Now we can calculate the acceleration using the formula:
a = (vf - vi) / t = (3.136 m/s - 0 m/s) / 0.32 s = 9.8 m/s^2
So, the correct value of acceleration for the dropped ball is 9.8 m/s^2, which is the acceleration due to gravity. If you obtained a value that is twice the actual value, there might have been an error in your measurements or calculations. Double-check your data and calculations to identify any mistakes.