Question

If the flight of a rocket can be modelled by the function h=-4.9t^2+49t+2.5. Where h is height in meters and t is time in seconds. How long was the rocket above 100m?
I know that you have to find the two times when the rocket hits 100m. And then subtract them. But how do you find the time when it hits 100m?
100=-4.9t^2+49t+2.5. How do you find the two t?

Answer 1

I know you can use the formula. But I'd there another way?

Answer 2

it's sad that it's 2021 and still no reply.