Validity of an experiment is based upon: a. performing a fair test, in which only the dependent variable affects the independent variable. b. using multiple independent variables. c. using a control group. d. performing a fair test in which only the independent variable affects the dependent variable.

D. Performing a fair test in which only the independent variable affects the dependent variable.

Explanation:

Validity is a measure of how correct the result of the experiment is. The validity of the experiment is based upon the correctness of the research topic, and correctness and implementation of the scientific procedures.  

Performing a fair test that can be based upon use of the independent and dependent variables can yield results which will be valid and acceptable. The independent variable in an experiment is the variable which can be changed to know it's affect on the dependent variable. The dependent variable will help in determining the result of the experiment.

! 55 !  

write a paragraph or story to explain the transformation between potential and kinetic energy as shown in your picture or model.  

you should have at least 5 complete sentences with a main idea and supporting details.  

you must include the following words:  

potential energy

kinetic energy

mechanical energy

conservation of energy

dude, this is hard lol : ))