Imagine a kid sitting in a soap box. The moment it tosses a stone away to the left, the soap box, along with the kid, moves to the right. If the kid pushes against the stone with a force of 20 N in the moment of the toss, what will be the acceleration of the system kid+soap box? The kid's mass is 50 kg and the soap box's 10 kg.

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)