How does the direction of the electric current, moving across a battery powered device, differ from the direction of travel in the ac current sent to homes and businesses?

The graph shown is a velocity-time graph of an object. what is the acceleration of the object from 6.0 to 10.0 seconds?

An ideal gas is held in a container at constant volume. initially, its temperature is 5 degrees c and its pressure is 1.2 atm. what is its pressure when its temperature is 43 degrees c? answer in units of atm

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