Question

A bumblebee can sense electric fields. The most likely mechanism underlying this sensitivity is motion of hairs on the bee’s body; the hairs bend in response to an electric field. Support for this mechanism as the source of the sensitivity is the fact that putting an electric charge on a bee (as occurs when a bee flies through the air) dramat- ically increases electric field sensitivity. Explain why adding charge to a bee would cause hairs on the bee’s body to bend more in response to a field.

Answer 1

Answer:

If the electrical field stays the same, the size of the electrical force on the bee's hair would be proportional to the size of the charge on it.

Explanation:

The question implies that:

1. The bee's hairs carry electrical charges.
2. The electrical field around the bee exerts a force on the bee's hair, causing them to bend.
3. The bee senses the electrical field by sensing the bend in its hairs.

Consider the bee's hair as a point charge. The force $\vec{F}$ between an electrical field and that point charge would be equal to

$\vec{F} = q \cdot \vec{E}$.

• the strength and direction of the electrical field, $\vec{E}$, and
• the size (and sign) of the charge on the object. $q$.

In this equation, the size of the electrostatic force $F$ is proportional to the size of $q$, the charge on the bee. Adding charge to the bee's hair would increase the size $q$. Even if the size of the field stayed the same, there would be an increase the size of $F$.

The hairs would now bend more since the force on them has become stronger. That means the bee would become more sensible to the electrical field.