- #1
chjoe0
- 2
- 0
A ball is thrown upward with velocity 30 ft/s on the roof of a 50 ft building - find the total time until the object meets the ground.
Heres my problem - I used the equation
x = (xsub0) + (vsub0)t + 1/2(a)t^2
I set xsub0 = 50, vsub0 = 30, and a = -9.8
I solved for t when x = 0, but the book gave a totally different answer.
Then I went back and used the equation given in the book:
[tex]\Delta[/tex]x = (vsubnot)[tex]\Delta[/tex]t + 1/2(a)([tex]\Delta[/tex]t)^2
I solved for [tex]\Delta[/tex]t when [tex]\Delta[/tex]x = 50, and my answer agreed
with the textbook solution...
My question is, why does the 2nd equation work in this situation, and how do I know when it is appropriate to use which?
Heres my problem - I used the equation
x = (xsub0) + (vsub0)t + 1/2(a)t^2
I set xsub0 = 50, vsub0 = 30, and a = -9.8
I solved for t when x = 0, but the book gave a totally different answer.
Then I went back and used the equation given in the book:
[tex]\Delta[/tex]x = (vsubnot)[tex]\Delta[/tex]t + 1/2(a)([tex]\Delta[/tex]t)^2
I solved for [tex]\Delta[/tex]t when [tex]\Delta[/tex]x = 50, and my answer agreed
with the textbook solution...
My question is, why does the 2nd equation work in this situation, and how do I know when it is appropriate to use which?