# Homework Help: Power output

1. Feb 6, 2010

### Precursor

1. The problem statement, all variables and given/known data
Calculate the power output of a 1.8-g spider(the black dot) as it walks up a windowpane at 2.3 cm/s. The spider walks on a path that is at $$25^{o}$$ to the vertical as illustrated below.

http://img19.imageshack.us/img19/4107/spiderl.jpg [Broken]

2. Relevant equations
P = W/t
F = mg

3. The attempt at a solution
P= W/t = Fd/t = Fv cos $$\theta$$ = mgv cos 25 = (0.0018 kg)(9.81 m/s^2)(0.023 m/s) cos25 = 0.00037 W.

Is this correct?

Thanks

Last edited by a moderator: May 4, 2017
2. Feb 6, 2010

### rl.bhat

While calculating the power you have not considered the angle given in the problem.
So W = F*v*cos(theta)

3. Feb 6, 2010

### Precursor

I have actually just editted my post after realizing this.