Final answer:
To move a copper box across a steel surface, the coefficient of static friction is needed to calculate the required force. Without this information, the question can't be accurately answered.
Step-by-step explanation:
To determine how much force is required to start moving a copper box weighing 20N across a steel surface, you need information about the coefficient of static friction between copper and steel. Unfortunately, this question does not provide the necessary detail or any additional context related to the frictional forces involved. If the question implies a situation where the static friction force is equal to the weight of the box (which would be unusual in practice), the force required would theoretically match the weight of the box. However, without the static friction coefficient or any other relevant data, the question cannot be accurately answered. Remember that in real-world scenarios, the required force is typically less than the weight of the object, as frictional forces are usually smaller than the gravitational force.