What is the best description of the acceleration of an object?

question 5 options:

a runner travels 100 m in one minute.

a car's velocity changes from 25 m/s to 20 m/s in 5 seconds.

an airplane changes elevation from 10,000 ft to 5,000 ft.

a remote-control car speeds up.

What is the number of atoms in 3.54 mol s

Classify this reaction: 2al+n2-> aln.

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.