When does the double-slit interference have its first dark spot on either side of the central peak intensity? a. when the paths d1 and d2 differ by one wavelength b. when the paths d1 and d2 differ by half a wavelength c. when the waves arrive in step, or “on phase,” with each other d. when the paths d1 and d2 have the same length

Aswimmer is determined to cross a river that flows due south with a strong current. initially, the swimmer is on the west bank desiring to reach a camp directly across the river on the opposite bank. in which direction shoud the swimmer head? a. the swimmer should swim southeast. b. the swimmer should swim south. c. the swimmer shuold swim northeast. d. the swimmer should swim due north. e. the swimmer should swim due east.

Which force would exist in a free body diagram of this car accelerating along the highway?

In an experiment, a die is rolled continually until a 6 appears, at which point the experiment stops. what is the sample space of this experiment. let en denote the even that n rolls are necessary to complete the experiment. what points of the sample space are contained in en? describe the event (∪ ∞ n=1en) c .