Frequency and wavelength

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? a. the wings are analogous structures that evolved differently and do not have a similar internal structure. b. the wings are homologous structures that evolved differently and do not have a similar internal structure. c. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. d. wings of bats are vestigial structures, but the wing structures of birds are not vestigial

The missing component to the table to the right or indicated with orange letters complete the table by filling in the corresponding numbers or symbols

Imagine that you push on a large rock. at what point does your effort change the rock’s mechanical energy?