7. The graph above shows how the speed of a book changes as it slides across a table in a
straight line. Over what time interval is the
net force on the book in the opposite direc-
tion of the book's motion?
A. O s to 0.5 S
B. 0.5 s to 2.4 s
C. O s to 2.4 s
D. 2 s to 2.4 s

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.

total distance/total time

(85 + 82)/(5+3)

167/8

20 just over

conservation of mass

mass before something happens = mass afterwards