SOLUTION: A ball is thrown vertically upward from the ground. Its distance in feet from the ground in t seconds is s=-16t+224t. After how many seconds will the ball be 720 feet from the g
Algebra.Com
Question 1158307: A ball is thrown vertically upward from the ground. Its distance in feet from the ground in t seconds is s=-16t+224t. After how many seconds will the ball be 720 feet from the ground?
please help!
Found 2 solutions by Boreal, jim_thompson5910:
Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
Note, I am assuming you meant s=-16t^2+224t
720=-16t^2+224t
16t^2-224t+720=0
divide by 16
t^2-14t+45=0
(t-9)(t-5)=0
when t= 5 and 9 seconds
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
Answer: Either t = 5 seconds or t = 9 seconds
=========================================
Work Shown:
The equation should be
s = -16t^2 + 224t
Note the t^2 term as the first term
Plug in s = 720. Then get everything to one side. Afterward, use the quadratic formula to solve for t.
s = -16t^2 + 224t
720 = -16t^2 + 224t
0 = -16t^2 + 224t - 720
-16t^2 + 224t - 720 = 0
Quadratic Formula: Plug in a = -16, b = 224, c = -720
or
or
or
or
or
or
We get two solutions because the ball goes up, but then comes back down again. At t = 5 seconds, the ball is going up. Then at t = 9 seconds, the ball is coming back down. At each of these time values, the height of the ball is 720 feet.
RELATED QUESTIONS
A ball is thrown vertically upward from the ground. Its distance in feet from the ground... (answered by Boreal,ikleyn)
a ball is thrown vertically upward from the ground. its distance in feet from the ground... (answered by nerdybill)
A ball is thrown vertically upward from the ground. Its distance in feet from the ground... (answered by Alan3354)
a ball is thrown vertically upward from the ground. its distance in feet from the gorund... (answered by Alan3354)
Can someone please help me out, howevever i am not good in algebra at all, especially... (answered by josmiceli)
I have a word problem that I have no idea how to do. can someone explain the steps to me? (answered by ankor@dixie-net.com)
A ball is thrown vertically upward with an intial velocity of 96 feet per second. The... (answered by Alan3354)
Please help me solve this:
A ball is thrown vertically upward from the top of a... (answered by nerdybill)
Assume that a ball is thrown vertically upward with initial velocity fo 96 ft per second. (answered by venugopalramana)