While no one knows why, astronomers do now know that long ago the solar nebula gained gravity deacreased in size increased in size collapsed

Standing side by side ,you and a friend step off a bridge at different times and fall for 1.6s to the water below. your friend goes first, and you follow after he has dropped a distance of 2.0m. when your friend hits the water, is the seperation between the two of you 2.0m or more than 2.0m? verify your answer with a calculation.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Which situation will produce the greatest change of momentum