Asked by Anonymous
A ball is thrown into the air from a height of 7ft. The height, h, of the ball after t seconds, is given by the equation h= −4.9t^2 + 34t + 7 .
What is the maximum height the ball reaches?
Select one:
a. between 45ft and 50ft
b. between 50ft and 55ft
c. between 55ft and 60ft
d. over 60ft (is this one correct?)
What is the maximum height the ball reaches?
Select one:
a. between 45ft and 50ft
b. between 50ft and 55ft
c. between 55ft and 60ft
d. over 60ft (is this one correct?)
Answers
Answered by
Damon
well I will cheat and use calculus
at to dh/dt = 0
0= -9.8 t + 34
t = 34/9.8 = 3.47 s
so
h= −4.9(3.47)^2 + 34(3.47) + 7
= -59 + 118 +7
= 66
so yes
at to dh/dt = 0
0= -9.8 t + 34
t = 34/9.8 = 3.47 s
so
h= −4.9(3.47)^2 + 34(3.47) + 7
= -59 + 118 +7
= 66
so yes
Answered by
Damon
h= −4.9t^2 + 34t + 7
parabola look for vertex
4.9 t^2 -34 t = -h + 7
t^2 - 6.94 t = -h/4.9 + 1.43
t^2 - 6.94 t + 12.0 = -h/4.9+ 13.43
(t-3.47)^2 = -h/4.9+ 65.8/4.9 = -(1/4.9)(h-65.8)
so t = 3.47 and h = 65.8 at vertex
parabola look for vertex
4.9 t^2 -34 t = -h + 7
t^2 - 6.94 t = -h/4.9 + 1.43
t^2 - 6.94 t + 12.0 = -h/4.9+ 13.43
(t-3.47)^2 = -h/4.9+ 65.8/4.9 = -(1/4.9)(h-65.8)
so t = 3.47 and h = 65.8 at vertex
Answered by
oobleck
−4.9t^2 + 34t + 7
the vertex is at t = -b/2a = 34/9.8
the height is h = c - b^2/4a = 7 + 34^2/19.6
the vertex is at t = -b/2a = 34/9.8
the height is h = c - b^2/4a = 7 + 34^2/19.6
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.