Final velocity?

Question

A bird accelerating from the rest at a constant rate, experiences a displacement of 28 m in 11 sec. What is the final velocity after 11 s?

I think it's zero, am I right??

please help thanks!

Answer 1

S=1/2 at^2
28m=1/2 a 11^2
28m=1/2 a 121s^2
56m=a 121s^2
56m/121s^2=a
a= .463m/s^2

2S=at^2
56m=a *121s^2
56m/121s^2=a
a=.463m/s^2


v=at
v=.463m/s^2*11s
v=5.093m/s

Final velocity at 11 sec is 5.093m/s

Answer 2

V=2*d/t

=2*28/11

Answer 3

no it is not zero. If the bird starts from rest and then speeds up the acceleration must be positive.
Use the equation X= Vot +1/2at^2
(X= displacement, Vo= initial velocity, a= acceleration, t=time)
X=28m t=11 s, Vo= zero m/s b/c the bird starts from rest
Therefore:
28=1/2a(11)^2
56/121=a
a=.46 m/s^2

Answer 4

s = ut + 1/2at^2
28 = (0 * 11) + (1/2 * a * 121)
28 = 60.5a
a = 28/60.5 = 0.463

v = u + at
= 0 + 0.463 * 11
= 5.093 m/s

Answer 5

i think you said it was accelarating
1/2at^2=s
1/2a*11^2=28
a=56/121
v=at=56/121 * 11 =56/11

Answer 6

s = 0.5at^2

28 = .5a * 121
56 = 121a
a = .4628m/s^2

v = at
v = .4628 * 11
v = 5.09m/s

edit: I found my own algebra error and fixed it - this version is correct. (I multiplied both the .5a and the 121 by 2, forgetting that it's really all one term, and you can't do that - whoops)