The earth is an oblate spheroid, but so close that it has a moment of inertia about its spin axis roughly equal to 2/5 MR2. R is the radius of the earth. The gravitational system acting on the oblate spheroid (tilted away from the orbital plane of motion by 23.45 degrees) is equivalent to a force F and a couple M. The effect of the couple is to make the earth precess about a perpendicular to the orbital plane (precession of the equinoxes). Given that the time for a complete precession of the equinoxes is 25800 years. Required:
Calculate the size of the couple (i. e the torque on the planet).

The energy released by a chemical reaction can be measured using a calorimeter. when barium hydroxide octahydrate crystals are reacted with dry ammonium chloride inside of a coffee cup calorimeter, the temperature of the 18.00 g of water in the calorimeter decreases from 30.0°c to 8.0°c. the equation for calculating energy absorbed or released by a reaction is: where q is the energy released or absorbed, m is the mass of water in the calorimeter, cp is the specific heat of water, and δt is the observed temperature change. if the specific heat of liquid water is 4.19 j/g·°c, how much energy was absorbed by the reaction?