A person is standing in an elevator which is moving down in constant speed. What is the correct relation between contact force, the weight of the person and the net force:

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.