A model rocket is launched with an initial upward velocity of 30/ms. The rocket's height h (in meters) after t seconds is given by the following.

h=30t-5t^2

Find all values of t for which the rocket's height is 10 meters.

Question

A model rocket is launched with an initial upward velocity of 30/ms. The rocket's height h (in meters) after t seconds is given by the following.

h=30t-5t^2

Find all values of t for which the rocket's height is 10 meters.

anonymous · Answer

All I have is 
$$-5t^2+30t=10$$

tkhunny · Answer

You should have some background in solving quadratic equations.

anonymous · Answer

Could you check my work for me? I think I know what to do.

anonymous · Answer

Subtract 10 from both sides to get -5t^2+30t-10 then factor

tkhunny · Answer

Please divide by -5 before proceeding.  Let's see you work so it can be checked.

anonymous · Answer

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I don't think it's right but that's what I would do with the quadratic equations I leave before??.