Question 339163
Hint: The acceleration of gravity is 9.8 m/s^2 (ie every second, a falling object speeds up by 9.8 m/s). Hopefully, this is mentioned in your book. So the equation that models the height of the helmet is {{{y=-9.8x^2+2x}}} where 'x' is the time and 'y' is the height. 



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