A train leaves Little Rock, Arkansas, and travels north at 80 kilometers per hour. Another train leaves at the same time and travels south at 65 kilometers per hour. How long will it take before they are 580 kilometers apart?
It will take hours.

Agroup of student volunteers participates in a study designed to assess several behavioral interventions for improving output in a repetitive task. prior to the beginning of the study, all volunteers unknowingly observed, and their output is measured. at the beginning of the study, prior to any intervention, the volunteers perform the same task under the observation of a study administrator, and their overall output increases. which of the following terms describes this phenomenon? a. simpson's paradox b. hawthorne effect are d. novelty effect d. pygmalion effect e. observer-expectancy effect