Posted by Mark on Wednesday, July 16, 2008 at 10:41pm.
A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is its acceleration?
A. 0.21
B. 0.46
C. 0.64
D. 0.78
E. 0.97
acceleration= change in velocity/change in time
and the velocity= change in displacement /change in time
Velocity=28 m/ 11 s= 2.5 m/s
Acceleration=2.5/11= 0.23 m/s^2
Which is close to Letter A, so the answer is letter A...is this correct?

Physics  drwls, Thursday, July 17, 2008 at 12:02am
The velocity you calculated is the average velocity. The acceleration is the FINAL velocity divided by the time interval. Use instead X = (1/2) a t^2
28 = (1/2)a t^2 = (1/2)*a*121
a = 28*2/121 = 0.46 m/s^2