Question

A falling object travels a distance given by the formula

Answer 1

Answer:

The time taken by object to travel 21 ft is 1 sec

Step-by-step explanation:

The distance travel by falling object given as

d = 5 t + 16 t²

The Distance cover by object to travel = 21 ft

so , from Distance time equation

21 = 5 t + 16 t²  

or, 16 t² + 5 t - 21 = 0

Or, 16 t² - 16 t +21 t - 21 = 0

Or, 16 t ( t - 1) + 21 (t - 1) = 0

Or.   (t - 1) (16 t + 21) = 0

Or,  (t - 1) = 0   And   (16 t + 21) = 0

∴      t = 1         And   t = (  $\frac{-21}{16}$  )

Hence The time taken by object to travel 21 ft is 1 sec Answer