Which statement about how light travels is true? a light waves need a medium to travel, and they travel at the same speed even if the light source is moving. b light waves can travel in a vacuum and travel at a constant speed even if the light source is moving. c light waves can travel in a vacuum and will travel faster if the light source is moving forward. d light waves need a medium to travel, and they travel faster if the light source is moving forward.

How many dots must be added to the symbol to properly represent a standard nitrogen ion? a) 1 b) 3 c) 5 d) 8

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.

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?