A partially-inflated balloon is fitted over the open end of a glass beaker that contains water. The beaker is placed over a flame, which heats the water and causes the balloon to expand. What are the correct signs for the heat and work changes to the beaker and balloon system?

A. -Q, +W

B. +Q, -W

C. +Q, +W

D. -Q, -W

From center station, a train departs every 30 minutes on the fast line and a train departs every 50 minutes on the state line. if two trains depart from center station at 8: 00 a.m., one on each of the two lines, what is the next time that two trains, one on each line, will depart at the same time?

According to newton’s first law of motion, which force is expected to cause a body to accelerate?

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