Finding Displacement with Constant Acceleration

[MemoIhad]

Hi there, I'm having a problem with this question, it seems like I'm doing everything perfect but still getting the wrong answer:

Homework Statement

During a 29.4-s interval, the velocity of a rocket changes from 204m/s [fwd] to 508m/s [fwd]. Assuming constant acceleration, determine the displacement of the rocket during this time interval.

Homework Equations

d=1/2(v1+v2)t

The Attempt at a Solution

t=29.4s
v2=508m/s [fwd]
v1=204m/s [fwd]
d=?

d=1/2(204+508)x29.4
=4,468.8m

This answer is wrong, the correct answer (based on the book) is 10500m [fwd]

THANKS!

 

[drpizza]

When I evaluate d=1/2(204+508)x29.4, I get 10500. (actually, 10466.4; rounded to 3 significant digits, it agrees) Your problem is apparently a calculator mistake - either hit a wrong button or you aren't typing it in correctly.

 

[MemoIhad]

Ya, I just re-did it, I got the correct answer, which is weird, because I re-tryed it 3 times and still got 4,468.8m, but suddenly I get 10500! I hate mistakes like this, it drives me crazy for no reason. THANKS for the quick reply! I can now stop being frustrated.