Respuesta :

240 = 0+1/2 (-9.8t

240 = -4.9t

240/-4.9 = t
49.0 = t

t= 7.0s

Answer:

7 seconds

Explanation:

Let's first write down what we have so that we can choose the correct equation of linear motion

initial velocity (u) = 0 m/s

distance (x) = h = 240 m

acceleration (a) = g = 9.81 m/s²

[tex]s = ut + \frac{at^{2} }{2} \\\\240 = (0)(t) + \frac{9.81t^{2} }{2}\\ \\9.81t^{2} = 480\\\\t = 6.99s\\\\t = 7 s[/tex]