Question

If a baseball player hits a baseball from 4 feet off the ground with an initial velocity of 64 feet per second, how long will it take the baseball to hit the ground? Use the equation h = –16t2 + 64t + 4.

Answer 1

does anyone understand it?

Answer 2

h represents the height of the ball from the ground.
so, when it hits the ground, what do you think the height will be equal to?

Answer 3

4?

Answer 4

so you think when it hits the ground then it will be 4ft off the ground?

Answer 5

i honestly don't know

Answer 6

just think about it, h represents the height of the ball from the ground. so when it is on the ground, what will its height be?

Answer 7

0?

Answer 8

correct - so now you just need to solve the quadratic equation resulting from setting h=0 in your equation.
i.e. solve this:\[0=–16t^2 + 64t + 4\]

Answer 9

okay

Answer 10

you should notice that all the terms can be divided by 4, so you can simplify it first by dividing the entire equation by 4 to get:\[0=-4t^2+16t+1\]

Answer 11

yes i got that !

Answer 12

so you can solve from here?

Answer 13

im doing it now

Answer 14

thankyouu

Answer 15

yw

Answer 16

can you help me on another one?

Answer 17

i already started on it but i got lost

Answer 18

<--- sure - just post it as a new question on the left