- #1
devilsangels287
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Homework Statement
Henrietta is going off to her physics class, jogging down the sidewalk at a speed of 4.20m/s . Her husband Bruce suddenly realizes that she left in such a hurry that she forgot her lunch of bagels, so he runs to the window of their apartment, which is a height 48.8m above the street level and directly above the sidewalk, to throw them to her. Bruce throws them horizontally at a time 4.50 secs after Henrietta has passed below the window, and she catches them on the run. You can ignore air resistance.
Q: With what initial speed must Bruce throw the bagels so Henrietta can catch them just before they hit the ground?
Q:Where is Henrietta when she catches the bagels?
Homework Equations
I placed the origin to be at the top of the picture. Where 48.8 would become 0. (I hope you understand what I mean)
So I know:
Vox= 4.20 m/s Voy= ?
Xo= 0m Yo = 0m
X = ? Y= -48.8m
g= 9.8 m/s^2
t= 4.5 secs t= 4.5 secs
I think that the x and y time are the same.
The Attempt at a Solution
So what I did was first find the x, so
X= Vox*t
X= 4.2*4.5
X= 18.9m
So that was suppose to answer part B question, but its wrong so I don't how else to do it.
And then for the part 1 question I did this
Y=Yo + Voy*t - (1/2)(g)(t^2)
-48.8= 0 + 4.5(Voy) - (1/2)(9.8)(4.6^2)
-48.8= 4.5(Voy) - 99.225
added both sides with 99.225
50.425 = 4.5Voy
Voy= 11.206 m/s
So I also thought that was correct, but it wasn't and don't any other way to do this. Please help me! Thanks.