The following are possible ways to express the quantity 0.391 (give all correct answers, i. e., b, ac, note: 3.45e-8 is a way you can enter the number 3.45×10-8 in most computers. a) 0.000391e4 b) 39.1 x 10-1 c) 0.391e+1 d) 3.91e-1 e) 0.0391e+1 f) 0.00391 x 102

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)