6000

Well, it would be effective (infinitesimally small, though) if the person was pile-driving the earth horizontally (from their point of view).

Angular momentum is conserved unless acted on by an external torque. Torque can be represented by the equation τ=RFsin(Θ). The sin(Θ) means that the torque is dependent on angle, with 90° having the maximum effect (sin(90)=1) and 0° having none. The effectiveness of the force you apply is also determined by how far from the axis of rotation you are pushing, which involves the moment arm. Think of it like opening a door. In order to cause rotation, you push along the doorknob. If you pushed the doorknob horizontally, nothing would happen because the angle of the torque would be 0° with the axis of rotation. Similarly, it is harder to open a door by pushing near the hinges than the doorknob because you are not utilizing the entire moment arm (which would be the radius of the Earth in this case). Not coincidentally, that is how levers work.

Anyway, nevermind.