Falling object, time between images

[physicscanbefun]

Homework Statement

Estimate the time between each photoflash of the apple in Fig. 2-18 (or number of photoflashes per second). Assume the apple is about 10 cm in diameter. [Hint: Use two apple positions, but not the unclear ones at the top.]

Homework Equations

All we have learned in class is the 3 kinematic equations but I haven't been able to figure this one out.[/B]

The Attempt at a Solution

I've tried plugging values into the kinematics but every time I'm missing too many variables to carry on.

 

[mfb]

I gave the thread a more descriptive title.

I've tried plugging values into the kinematics but every time I'm missing too many variables to carry on.

Please show your work, otherwise it is impossible to tell what went wrong.