1.Calculate the kinetic energy that the earth has because of (a) its rotation about its own axis and (b) its motion around the sun. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used in the United States in one year is about 1.1 x 10²⁰ J

2.A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible alternative to batteries in electric cars. The gasoline burned in a 425-mile trip in a typical midsize car produces about 3.43 x 10⁹ J of energy. How fast would a 6.63-kg flywheel with a radius of 0.293 m have to rotate to store this much energy? Give your answer in rev/min

3.The drawing shows three identical springs hanging from the ceiling. Nothing is attached to the first spring, whereas a 4.24.2-N block hangs from the second spring. A block of unknown weight hangs from the third spring. From the drawing, determine (a) the spring constant (in N/m) and (b) the weight of the block hanging from the third spring.

4.A person who weighs 792 N steps onto a spring scale in the bathroom, and the spring compresses by 0.738 cm. (a) What is the spring constant? (b) What is the weight of another person who compresses the spring by 0.331 cm