astronomers use the gravitational wobble of a star to indicate the presence of planets outside our solar system. astronomers specifically look for planets in the habitable zone of 1.6 x 1011 m away from the star. calculate the mass of a planet that exerts a 1.5 x1013 n force on a 5.4 x 1030 kg star.

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