1. The Earth spins one full rotation every 24 hours. You, a madscientist bent on destroying the world, wish to make \"Earth standstill\" - you want to make it stop rotating. In your arsenal, youhave lots and lots of rocket engines that you are free to placehowever you wish around the Earth. How will you arrange theserockets to stop the Earth's rotation (where will you put them, howwill you orient them)? How much total thrust will you need to stopthe rotation? Assume the Earth is a uniform sphere. You can findthe mass and radius of the Earth, and you will need the moment ofinertia through a sphere's center of mass, which you can also findon Google.
2. When an object rolls without slipping, the static frictionacts antiparallel to the direction of motion. Why don't we usuallyworry about the (negative) work done by the static friction on therolling body? Hint: How does the rotational work done by the staticfriction compare? It will help to set up an example problem andcalculate the quantities explicitly to compare them.
