# Question #2ba09

Jan 31, 2018

That’s an unusually small bird, but the physics remains constant.

#### Explanation:

Power, $P = F \times v$ but be careful, in this case the F is weight, $w = m \times g$

[I think there may be a secondary problem underlying this, that the formula above is derived from power = work done / time = $\frac{E}{t} = \frac{\vec{F} . \vec{s} \cos \theta}{t}$ and as the force (gravity) is perpendicular to the velocity (assumed horizontal) no work is done! Invalidating the expression for E means we may have an incorrect assumption, despite the power equation being a dot (scalar) product - I’ll request a double-check]

So $w = m \times g = 0.001 \times 9.81 = 0.0098$N

And $P = F \times v = 0.0098 \times 0.5 = 0.0049$W or roughly 5 mW