The equation above expresses the approximate height h in meters of a ball, t seconds after it is launched vertically upward from the ground with an initial velocity of 25 meters per second. After approximately how many seconds will the ball hit the ground? Alright, so we got to figure this out using this equation where h is the height of the ball during its path. And t is the time it has taken during its journey. Alright, and they're asking us, how long would it have taken to hit the ground again, so it's starting here. Let's go and up on its merry way and hits back.

Okay. So what you got to ask yourself is, what will my HP what will the height of the ball be when it hits the ground? Well, seems a little obvious when it hits the ground, our H is going to be zero. That's just going to be here. Okay. You can think of it as an axis where this is h and this is T. All right, so if H is zero, what will be my time Let's just plug it in.

And if we plug in zero here, then we will get the following. We will get zero is equal to negative 4.9 t squared plus 25 T, we add 4.9 t squared each side, then we'll get 4.9 t squared is equal to 25 t divided by T, we'll get 4.9 t is equal to 25. And if we try to solve for t, well 4.9 is really just five. It's pretty close to fly. So you can do that. So 25 divided by five will give you a team of five.

That's all very, very straightforward and simple.