Jorge is kicking a ball straight up into the air. The height of the ball is described by the equation h=-16t^2+20t, where h is the height of the ball and t is the time in seconds. How long will it take the ball to hit the ground?

Grace_for_Mom
Mar 15, 2017

#1**+5 **

Use desmos. XD

Or:

I think you should simplify it so that you get 5t-4t^{2} = 0. After all, when the ball hits the ground, the height should be 0. You can then say, with the above equation, that 5t = 4t^{2}, since adding 4t^{2} to either side will give you that. Then, you can say that 1.25t = t^{2}, after you divide each side by 4. Divide each side by t, and you get the solution: t = 1.25.

Guest Mar 16, 2017

#1**+5 **

Best Answer

Use desmos. XD

Or:

I think you should simplify it so that you get 5t-4t^{2} = 0. After all, when the ball hits the ground, the height should be 0. You can then say, with the above equation, that 5t = 4t^{2}, since adding 4t^{2} to either side will give you that. Then, you can say that 1.25t = t^{2}, after you divide each side by 4. Divide each side by t, and you get the solution: t = 1.25.

Guest Mar 16, 2017