A roofer needs to get shingles onto a roof. Pulling the shingles up manually uses 1,549 N or force. The roofer decides to use a system of pulleys. Using the pulleys, 446 N are required to lift the shingles. What is the mechanical advantage of the system of pulleys?

Place several e-field sensors at a few points on different equipotential lines, and look at the relationship between the electric field and the equipotential lines. which statement is true? 1-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of higher voltages. 2-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of lower voltages. 3-at any point, the electric field is parallel to the equipotential line at that point.