[ 545 ] Physical Science GED ® TEST SCIENCE FLASH REVIEW • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A man pushes a box horizontally across a frictionless surface for 15 m. He does 150 J of work. How much net force did he apply to the box? A. 15 N B. 10 N C. 150 N D. 1.0 N In a physics experiment, a student makes several measurements of the velocity of a sound wave from a tuning fork. The measurements (in m/s) are: 341, 343, 330, 335, 338, 345, 341 What is the mean of the sample data set? A molecular biologist wanted to make an artificial peptide containing three amino acids (there are 20 possible naturally occurring amino acids that he could use). Without repeating any amino acids, how many permutations are there? A. 1,140 B. 6,840 C. 7,980 D. 3.2 million