A roller coaster moves slowly at the top of a hill and increases as it moves down the hill increasing its kinetic energy. Where did this increasing kinetic energy come from? a. The people and their belongings in the cars
b. The wind behind the cars
c. potential energy was transformed into kinetic energy
d. kinetic energy was added by a motor pushing the cars

Assume you measured the mass of the cart to be (500 ± 1) g and the mass of the additional mass you put on the cart to be (500 ± 1) g as well. since the scale you are using in the lab cannot measure objects heavier than 600g you will have to sum up individual pieces and propagate the error. so what would be the mass and the standard error of the cart and the mass