Which circuit does not allow current to flow through it?

An observer that stands still as the electron moves by him, will observe

How have the competing explanations' experiments on atoms affected the development of the atomic model?

Standing side by side ,you and a friend step off a bridge at different times and fall for 1.6s to the water below.your friend goes first,and you follow after he has dropped a distance of 2.0m.when your friend hits the water,is the seperation between the two of you 2.0m or more than 2.0m? verify your answer with a calculation.