John's grandfather clock has a pendulum that keeps the seconds. what does this graph say about the observed pattern of motion?

a) the pendulum swings with a constant velocity.

b) the vacillating periodic motion changes sign.

c) the pendulum displays a constant acceleration.

d) the oscilations show a variable rate of motion.

Which of the following is true about fossils? a. fossils found in lower layers of sedimentary rock are older than fossils found in upper layers of sedimentary rock. b. fossils found in lower layers of sedimentary rock are as old as fossils found in upper layers of sedimentary rock. c. the relative age of fossils cannot be determined from their position in sedimentary layers.