your data does not match the equation , so I don't know which is the correct one
I will go with the equation:
h = -4t^2 + 8.1t + 3 , (according to your data it would be 8.2t)
when h = 6
6 = -4t^2 + 8.1t + 3
4t^2 - 8.1t + 3 = 0
using the formula:
t = (8.1 ± √17.61)/8
= 1.53 sec or .49 sec.
(one is on the way up, the other on the way back down)
The question asked how long it would take to reach a height of 6 m, so that would be .49 sec.
A toy rocket is launched form a 3m platform, at 8.2m/s. The height of the rocket is modelled by the equation h=-4.0t^2+8.1t+3 where h is the height, in metres, above the ground and t is the time, in seconds.
After how many seconds will the rocket rise to a height of 6m above the ground?
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