As an airplane is taking off at an airport its position is closely monitored by radar. the following three positions are measured with their corresponding times: x1 = 135.94 m at t1 = 3.20 s,
x2 = 169.39 m at t2 = 3.70 s,
x3 = 206.88 m at t3 = 4.20 s.
what is the acceleration of the airplane at t2 = 3.70 s? (assume that the acceleration of the airplane is constant.)

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.