Jaclyn plays singles for smith's varsity tennis team. during the match against north, jaclyn won the sudden death tiebreaker point with a cross court passing shot. the 67.5 gram ball hit her racket with a northward velocity of 26.7m/s. upon impact with her 331 gram racket, the ball rebounded in the exact opposite direction (and along the same general trajectory) with speed of 29.5 m/s

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

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.

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".