Planets are not uniform inside. normally, they are densest at the center and have decreasing density outward toward the surface. model a spherically symmetric planet, with the same radius as the earth, as having a density that decreases linearly with distance from the center. let the density be 1.20×104 kg/m3 at the center and 2100 kg/m3 at the surface. what is the acceleration due to gravity at the surface of this planet?

g= ? m/s^2

An athlete swings a ball, connected to the end of a chain, in a horizontal circle. the athlete is able to rotate the ball at the rate of 8.13 rev/s when the length of the chain is 0.600 m. when he increases the length to 0.900 m, he is able to rotate the ball only 6.04 rev/s. (a) which rate of rotation gives the greater speed for the ball? 6.04 rev/s 8.13 rev/s (b) what is the centripetal acceleration of the ball at 8.13 rev/s? m/s2 (c) what is the centripetal acceleration at 6.04 rev/s? m/s2