1. The problem statement, all variables and given/known data The earth's axis of spin precesses just like that of a top or a gyroscope. (This is why the North Star moves away from the north over many centuries.) The cause is the torque on the earth due to the gravitational pull of the moon and the sun on the earth's equatorial bulge. The time for a complete cycle of this precession is 2.60×104 years. How much combined torque do the sun and moon exert on the earth to cause the observed precession? 2. Relevant equations Torque=r*f 3. To find the combined torque, i had to find the force that the sun exerts on the earth. I did this by finding the gravitational force which was 6.674*10^-11 ((1.9891*10^31 kg)(5.97*10^24kg))/ (149600000 km*1000)^2 the force should equal 3.53 *10^22 N the moon equals out to be 1.98 *10^20 Now i have the forces so i plug it into the equation t=r*f t= 3.53 *10^22 N *1.49*10^11 m=5.28*10^33 Moon: t= 1.98*10^20 N * 384403000m=7.6*10^28 The combined torque would be 7.6*10^28 + 5.28*10^33 = 5.28*10^33 Am i using the wrong equation to find the force of the moon and sun exerted on the earth?????