If you started with a 125g sample of U-235, how much of the sample would be remaining after 3 half-lives and how many years would have passed? (AKS 4b, DOK 1)
O A. 15.6g would remain after 2100 million years had passed.
O B. 12.5g would remain after 3000 million years had passed.
O C. 12.5g would remain after 2100 million years had passed.
D. 15.6g would remain after 3000 million years had passed.

1) a child holds two dogs on two separate leads. the dogs are pulling in different directions. one is pulling a force of 20n north and one is pulling 15n eastwards. calculate the resultant force on the child. state the direction. (use the parallelogram of forces) 2) a force of 20n acts horizontally on an object. a second force of 5n acts at 60 degrees to the first one. calculate the resultant force. worth 20 points, need answers asap with method you x