1. The problem statement, all variables and given/known data If you had a simple pendulum of length 1 m and mass 5e-3 kg placed in a uniform electric field E that is directed vertically upward. The bob has charge of -8e-6 C. the period is 1.2 s what are the magnitude and direction of E? First, didn't they already tell us that E is directed vertically upward, so wouldn't the direction of E be vertically upward? Though wouldn't there be a force downward on the charge from E if that is the case? Also, I thought that the period for the simple pendulum is sqrt(L/g), where L is the length measured from the pivot and g is gravity. So here sqrt(L/g) doesn't come out to be 1.2 s? Would the force from the Field qE = the torque that causes it to oscillatte (but can we ignore gravity?) And since F = ma, so we know that qE/m = a. And we also know that the angular acceleration on a pendulum is Lmgsin(theta)/I, where I is the moment of inertia of the pendulum. So does this mean that the two are equal (after I multiply the angular acceleration by L)? But then what about theta? Thanks.