If similar fossil collections are found on two continents, now widely separated, what is a possible explanation?

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

Aballet student who learns with the of his instructor is demonstrating learning.

Unpolarized light of intensity so passes through two sheets of polarizing material whose transmission axes make an angle of 60∘ with each other as shown in the figure. what is the intensity of the transmitted beam, st?