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2 votes
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The height, h, in metres, of a rocket t seconds after it is launched is approximately modelled by the quadratic relation h = 80t - 16t2. To the nearest second, how long is the rocket in the air?

User John Arlen
by
2.6k points

1 Answer

9 votes
9 votes

Answer: 5 s

Explanation:

Given

Height of the rocket can be modelled as
h=80-16t^2

Rocket will land on earth when it's height becomes 0


\Rightarrow 80t-16t^2=0\\\Rightarrow t(80-16t)=0\\\\\Rightarrow t=0\ \text{or}\ t=(80)/(16)=5\ s

Neglecting 0 value

Thus, rocket remains in air for 5 s.

User Cosmin Cosmin
by
3.2k points
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