Question 1149549
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x = number of seconds
y = free-fall speed of object in meters per second (m/s)
y = 9.8*x since the approximate acceleration is 9.8 m/s^2, meaning that each second, the object is falling roughly 9.8 m/s faster


Plug in y = 72 and isolate x
y = 9.8x
72 = 9.8x
9.8x = 72
x = 72/9.8
x = 7.3469387755102 which is approximate
x = 7.3


It takes <font color=red>roughly 7.3 seconds</font> for the object's falling speed to be 72 m/s.


Note: I rounded to one decimal place as the given value 9.8 is reported at one decimal place.
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