Read the scenario.
a group of scientists decides to conduct research to see whether access to a higher amount of a certain vitamin will improve the health of lab rats. they raise more than 500 rats, giving some the extra vitamin and some not, and keep track of how often the rats are sick and how long they live. the scientists’ findings are positive; the rats are healthier and live longer when they have access to the vitamin.
which option correctly identifies why this research was scientific?
a )the scientists researched a common situation and came to an interesting conclusion.
b )the scientists used proper ethical guidelines while performing their research.
c )the scientists’ question was testable, and their claim was based on evidence.
d )the research topic was generally important for people and could increase the quality of life for many.

Atennis player used a tennis racket to hit a tennis ball with a mass of 0.25 kg with a force of 5.25 newtons. how does the force the tennis racket exerted on the tennis ball compare with the force the tennis ball exerted on the tennis racket? a. the force of the tennis racket on the tennis ball is equal in magnitude and opposite in direction to the force the tennis ball exerted on the tennis racket. b. the force of the tennis racket on the tennis ball is equal in magnitude and in the same direction as the force the tennis ball exerted on the tennis racket. c. the force of the tennis racket on the tennis ball is less in magnitude and in the same direction as the force the tennis ball exerted on the tennis racket. d. the force of the tennis racket on the tennis ball is greater in magnitude and opposite in direction as the force the tennis ball exerted on the tennis racket.