Answer: 0.2m
Explanation: Firstly only the Rocket's Weight Compress the spring which can be found by

According to Hooks Law

The part b and c of this question is done in the attachment
They have thick body coverings
Answer:
D
Explanation:
- The rate of the Diels-Alder is orders of magnitude faster if there is an electron-withdrawing group on the dienophile. For example, replacing a hydrogen on ethene with the electron-withdrawing group CN results in about a 10^5 increase in the reaction rate.
- Other common electron withdrawing functional groups that will accelerate the Diels Alder reaction of dienophiles include aldehydes, ketones, and esters.
- In short, any functional group conjugated with the pi bond which can act as a pi acceptor will accelerate a Diels-Alder reaction with a typical diene.
- See attachment for graphical explanation.
D. The atomic mass in amu is basically the number or nuclei since the mass of the electrons is negligible. For a given atom (element) the number of protons is fixed. Say the element has 10 protons. If the atomic weight is 14 atomic mass units (amu), you know that there are 4 neutrons, since both neutrons and protons are 1 amu each and there are 10 protons