A charged particle moving in a magnetic field experiences a force equal to:
Thus, the magnitude of the force that the proton experiences is given by:
The magnetic field is perpendicular to the proton's velocity, therefore, we have 
. Replacing the given values, we obtain:
The peppered moth is a temperate species of night-flying moth. Peppered moth evolution is an example of population genetics and natural selection.
Work in general is given by W=F·d where F is the force vector and d is the displacement vector. The dot symbol is the dot product which is a measure of how parallel two vectors are. It can be replaced by the cosine of the angle between the two vectors and the vectors replaced by their magnitudes. If F and d are parallel then the angle is zero and the cosine is unity. So in this case work can be defined as the product of the magnitudes of the force and distance:
W=Fd
