1. A train travels 72 km, north along a straight track in 28 minutes. What is the train's average velocity in kilometers per minutes?

World class speed skaters can skate a 3,000-m course in about 4 minutes.what is their average speed for this course? a. 12.5 m/sb. 1.33 m/sc. 1.25 m/sd. 13.3 m/s

What would be the result of an alpha particle coming into a magnetic field? a) the alpha particle will stop moving. b) the alpha particle will reverse its direction. c) the alpha particle will be deflected in a curve path. d) the alpha particle will continue to travel in a straight line.

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value