NaazB_3.1415
New member
- Joined
- Aug 6, 2020
- Messages
- 8
Hey I'm having trouble with this question:
"With what initial velocity must an object be thrown vertically upward in order to reach a man on a scaffold 15ft above?"
PS. I think this is a British calculus textbook so they use -32 ft/s^2 , instead of the -9.8m/s^2.
I tried solving this like this:
s(t) = -16t^2 + Vot (Vo is initial velocity)
V(t) = -32t + Vo
a(t) = -32
I reasoned that the initial velocity occurs when t=0, v(0) = Vo
and occurs when the displacement is equal to zero
0 = -16t^2 + Vot
0 = t(-16t + Vo), here I'm left with 2 unknowns so I don't know how to progress from here.
If I try to solve this from an algebraic physics perspective I get:
Vf^2 = Vo^2 + 2ad
0 = Vo^2 + 2(-32)(15)
960 = Vo^2
-31ft/s = Vo
I don't even know if this is correct because my book doesn't have the solution to this question.
Thanks
"With what initial velocity must an object be thrown vertically upward in order to reach a man on a scaffold 15ft above?"
PS. I think this is a British calculus textbook so they use -32 ft/s^2 , instead of the -9.8m/s^2.
I tried solving this like this:
s(t) = -16t^2 + Vot (Vo is initial velocity)
V(t) = -32t + Vo
a(t) = -32
I reasoned that the initial velocity occurs when t=0, v(0) = Vo
and occurs when the displacement is equal to zero
0 = -16t^2 + Vot
0 = t(-16t + Vo), here I'm left with 2 unknowns so I don't know how to progress from here.
If I try to solve this from an algebraic physics perspective I get:
Vf^2 = Vo^2 + 2ad
0 = Vo^2 + 2(-32)(15)
960 = Vo^2
-31ft/s = Vo
I don't even know if this is correct because my book doesn't have the solution to this question.
Thanks