Can someone pls help me with these questions pls and for 8 and 9 if u could explain the answer I would really appreciate it. I’ll give brainliest

What is the magnitude of the resultant vector round your answer to the nearest tenth

If a stone with an original velocity of 0 is falling from a ledgeand takes 8 seconds to hoybthe ground whays the final velocity of the stone

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