Input energy is: 200 joule
Output energy is: 100 joule
100/200*100=%50 efficiency
The catalyst lowers the activation energy.
Answer: Can I get a picture???
Yes, it is because gravity is a force of attraction to the center of our planet, Earth. If we drop a pencil, the pencil will go on the floor. Gravity is pulling the pencil down.
Your mass will never change despite if you go to Jupiter, Uranus, Mars, Earth, or any planet.