If a stone is thrown vertically upward from the surface of the moon with a velocity of 10 m/s, its height (in meters) after t seconds is h(t)=10t−0.83t^2
What is the velocity of the stone after it has risen 25 m?

Question

If a stone is thrown vertically upward from the surface of the moon with a velocity of 10 m/s, its height (in meters) after t seconds is h(t)=10t−0.83t^2 
What is the velocity of the stone after it has risen 25 m?

anonymous · Answer

Am I just supposed to set h(t) = 25 and solve the quadratic for t and then plug that t in the derivative of h(t) ?

jim_thompson5910 · Answer

Yes you have the correct line of thinking.

anonymous · Answer

Awesome! But solving the quadratic I will get 2 values for t, which one should I plug in?

jim_thompson5910 · Answer

|dw:1433569730753:dw|