Who is credited with being the first person to accurately determine earth's circumference?

Which of the following statements is true about women and minorities in early psychology? a. in the early 20th century, numerous graduate schools recruited women and minorities to study psychology. b. opportunities in higher education were limited for women and minorities in the early 20th century due to discrimination. c. despite some obstacles, there were numerous employment opportunities for women and minorities. d. women and minorities were often selected to do academic research in an effort to make the field more diverse.

If the ama of the inclined plane below is 2, calculate the ima and efficiency. ima = efficiency =

Light traveling in water, nwater = 1.33, strikes a plastic block at an angle of incidence of 51.4°; part of the beam is reflected and part is refracted. if the index of refraction of the plastic is 2.0, what is the angle made by the reflected and refracted beams?