Question

The velocity of a ball thrown vertically upwards\ from ground level is v(t)= -32t^2 + 64t, where t is the time in seconds and v is the velocity in feet per second.
Find the time when the ball reaches its maximum height (Find the vertex of the parabola using x= -b/ 2a

Answer 1

Well, it gives you the hint -b/2a. Well, a norma quadratic function is
ax^2 + bx + c
The number in front of the x^2 is 'a" and the number in front of x is b. Except for you you have t, but same thing. So in your case, b is 64 and a is -32. So plugging those into the formula will give you the time it takes to reach the maximum height.

Answer 2

So if done correctly, you should have -64/-64 = 1. Which means it is at its maximum height after 1 second. In order to actually find that height, you replace t with 1 in the original equation, meaning you solve -32(1)^2 + 64(1) = ?

Answer 3

-960

Answer 4

sorry wrong

Answer 5

Take your time :3

Answer 6

is that a plus sign ?

Answer 7

-32(1)^2 + 64(1)

So yeah, plus sign in the middle.

Answer 8

32

Answer 9

Yep : )

Answer 10

perfect, thank you (:

Answer 11

no problem :3