In order to make vehicles more energy efficient, what can be done?

What is the difference between electrically neutral objects and electrically charged objects

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.

Brutus, the dog, is pulling a bone to the left with a force of 20 n. lassie, another dog, is pulling a bone to the right with a force of 18n. what is the net force? a. b. c.