20 points plz help i dont really understand how to do this my grades at d rn plz help lol tysm if you do < 3

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

What is the scientific definition of energy that relates to work

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up