Hello if there's any chemistry buffs out there i linked a little worksheet im struggling with, if someone could kindly give me the answers :)

Naoki's bicycle has a mass of 10 kg. if naoki sits on her bicycle and starts pedaling with a force of 168 n, causing an acceleration of 2.8 m/s2, what is naoki's mass?

Ase your answer to this question on the information below. hydrocarbons and fissionable nuclei are among the sources used for the production of energy in the united states. a chemical reaction produces much less energy than a nuclear reaction per mole of reactant. the balanced chemical equation below represents the reaction of one molecule of a hydrocarbon with two molecules of oxygen. chemical equation: ch4 + 2o2 → co2 + 2h2o + 1.48 × 10−18 jthe nuclear equation below represents one of the many possible reactions for one fissionable nucleus. in this equation, x represents a missing product. nuclear equation: write an isotopic notation for the missing product represented by x in the nuclear equation.

Which statement describes the phase change that occurs when dry ice is placed in an open container at room temperature?