Zooplankton populations in Lake Erie and the Hudson River have declined by up to 70% since the arrival of zebra mussels because . Group of answer choices Zebra mussels feed on phytoplankton, which zooplankton need as a food source Zooplakton are reduced due to predator mediated competition Zebra mussels block sunlight penetration into lakes and thus prevent zooplankton from photosynthesizing Zebra mussels prey exclusively on zooplankton Zooplankton are replaced due to competitive exclusion

40 N/C, downward

Explanation:

- Magnitude:

The relationship between the force experienced by a charge and the electric field strength is given by

F=qE

where

F is the force

q is the charge

E is the electric field strength

In this problem, we have

q = 0.05 C is the charge

F = 2 N is the force exerted on the charge

By solving the formula for E, we find the magnitude of the electric field:

E=\frac{F}{q}=\frac{2 N}{0.05 C}=40 N/C

-Direction:

The direction of an electric field corresponds to the direction of the force that would be exerted on a positive charge immersed in the field. Therefore, for a negative charge, the electric field and the electric force have opposite directions.

Since the charge in the problem is negative, and since the charge is pushed upward (so, the force is upward), the electric field must be downward.