# Average speed that you observe for the button as it falls

1. Feb 13, 2005

You are at an airport watching people go by on a "people mover" conveyer belt that moves at a constant speed of 0.60m/s. As a person goes by, they drop a button from a height of 1.2m. What is the average speed that you observe for the button as it falls to the ground?

well i have:
x=1.2m
v=0.60 m/s
a = 0

so i'll use this formula:

V^2=v(0)^2 +2a(x-x(0))

well a is 0 so the right side cancels to zero.

and v(0) = 0.60

so that means the answer is 0.60m/s, but it's incorrectly. the answer should be 2.5m/s. can someone tell me what i'm doing wrong?

2. Feb 13, 2005

### vsage

Where's the movement in the y direction?

3. Feb 13, 2005

$$v_{avg} = \frac {\int _0 ^T [v_x^2(t) + v_y^2(t)]^{1/2}dt }{T}$$