PLEASE HELP ME I DONT UNDERSTAND THIS AND THIS IS TIMED In an experiment, a rubber stopper is attached to one end of a string. The stopper is whirled in a horizontal circular path of a diameter of 1.0 meter at a constant speed. The stopper completes one revolution in 0.2 seconds. Approximately what is the magnitude of the stoppers speed?

A) 3.1 m/s
B) 6.3 m/s
C) 16 m/s
D) 31 m/s

(C)

Explanation:

The circle has a radius r = 0.5 m, which means that its circumference C is

One revolution means that the stopper travels a distance equal to the circumference of the circle so the velocity of the stopper is

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.