Which of the following is an example of velocity? question 15 options: a plane travelling south towards the bahamas. a man running 7 miles per hour west. a car sitting at a stop sign? a dog running at 5 miles per hour.

Light waves travel than sound waves.

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.

Which of the following is in the lanthanide family? a) uranium b) promethium c) silver d) gold