The Sears Tower in Chicago is 443 m tall. Joe wants to set the world’sstair climbing record and runs all the way to the roof of the tower. If Joe’saverage upward speed is 0.60 m/s, how long will it take Joe to climb fromstreet level to the roof of the Sears Tower?

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.)