8. The moon moves around the earth. What kind of motion does the moon demonstrate? A rectilinear B. rolling C. circular D. periodic 9. The swing moves back and forth, up and down. What kind of motion has the swing? A. periodic B. rectilinear C. rolling D. circular 10. Which of the following affects the motion of an object? A. push B. pull C. friction D.all of the above 11. A force is described as A. a push only B. a pull only C. a push or a pull D. none of the above 12. Making a playground slide smoother A. decreases friction B. decreases motion C. decreases speed D. decreases weigh 13.An object thrown upwards falls because of A. gravity B. pull C. friction D. push 14. Which of the following is a measure of speed? A. km B. min C. m/s D. cm 15. What does the measurement 92 meters per second refer to? A. distance B. time C. speed D. all of the above 16.To find the speed of an object, you need to know the distance and A. force B. position C. time D. friction on :