# Posts by Maa

Total # Posts: 3

**physics**

Find the rotational kinetic energy of the earth about the sun due to its orbit about the sun. The mass of the earth M is 6 x 1024 kg, the orbital radius r is 1.5 x 1011 m and the rotational period T is 1 year. Treat the earth as a point mass in this problem

**physics**

A constant torque of 20 N.m is applied to a wheel pivoted on a fixed axis. At what rate is power being furnished to the wheel when it is rotating at 0.5 rev/sec?

**physics**

A force of 100 N is applied tangentially to a disk of radius 10 cm and mass 0.5 kg. the disk is initially at rest. What is the angular acceleration of the disk? How many revolutions does the disk goes through after 10 sec. How much rotational work was done on the disk?