A cross-country skier moves 32 meters westward, then 54 meters eastward, and finally 68 meters westward. Whats the magnitude.

Explanation:

It is given that, a cross-country skier moves 32 meters westward, then 54  meters eastward, and finally 68 meters westward.

The attached figure shows the whole scenario. He starts walking 32 m west and finally it walks 68 m west.

Let west is negative and east is positive.

Displacement = final position - initial position

= -68 - (-32)

= -36 m

The magnitude of displacement is equal to 30 m westwards.

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.