ex. 1 A spaceship is traveling at 25m/s when its reverse rockets are fired causing a backward acceleration of 9.80m/s2. How fast is it going after 2.0s? How fast is it going after 4.0s? ex. 2 A man stands at the edge of a cliff and throws a rock straight up so that on its way down it falls past him and continues downward. The initial velocity of the rock is 30m/s, and round the acceleration of gravity to 10m/s2. Compute the velocity and displacement at the following times. ex. 3 A ball thrown vertically upward is caught by the thrower after 2.00s at the same height it was thrown. Find (a) the initial velocity of the ball and (b) the maximum height it reaches. HW 7 38) 3.94s 43) a) 2.33s b) 32.9m