Two descriptions about physical quantities are given below: Quantity A: It has the same unit as force. Quantity B: It measures the amount of matter in an object. What quantities are these most likely describing? (4 points) Both Quantity A and Quantity B are mass. Both Quantity A and Quantity B are forces. Quantity A is weight and Quantity B is mass. Quantity A is mass and Quantity B is weight.

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