A student throws a set of keys vertically upward to his fraternity brother, who is in a window 4.05 m above. The brother's outstretched hand catches the keys 1.45 s later. (Take upward as the positive direction. Indicate the direction with the sign of your answer.) (a) With what initial velocity were the keys thrown? (b) What was the velocity of the keys just before they were caught?

A juggler throws balls straight up in the air. After the balls leave his hand and while it is in the air, explain WHY each of the following four statement is FALSE. Write the right answer. (a) The velocity of the ball is always in the same direction as it's acceleration. (b) The velocity of the ball is never in the same direction as it's acceleration. (c) The acceleration of the ball is zero. (d) The velocity of the pin is the same direction as it's acceleration on the way up.

Two students are on a balcony a distance h above the street. The first student throws a ball vertically downward at a speed v0; at the same time, the second student throws a ball vertically upward at the same speed. Answer the following symbolically in terms of v0, g, h, and t. (a) Write the kinematic equation for the y-coordinate of each ball. (Let up be positive.) y1 =                            (ball 1) y2 =       (ball 2) (b) Set the equations found in part (a) equal to height 0 and solve each for t symbolically using the quadratic formula. What is the difference in the two ball's time in the air? (Remember that t must always be a positive quantity.) t2 − t1 =                         (c) Use the time-dependent kinematics equation to find the velocity of each ball as it strikes the ground. v1 =                    (ball 1) v2 =       (ball 2) (d) How far apart are the balls at a time after they are released and before they strike the ground?…

Attempting to run out the clock in a basketball game, a player throws the ball straight up from height yo. An opposing player catches the ball coming down, at the same height. How much time was used up while the ball was in the air? [Data : yo = 1.20 m; maximum height of the ball = 7.32 m ] Submit Answer Tries 0/12

A mountain climber stands at the top of a 35.0 m cliff that overhangs a calm pool of water. She throws two stones vertically downward 1.00 s apart and observes that they cause a single splash. The first stone had an initial velocity of -1.20 m/s. (a) How long after release of the first stone did the two stones hit the water? (Round your answer to at least two decimal places.) 7.14 Your response differs from the correct answer by more than 100%. s (b) What initial velocity must the second stone have had, given that they hit the water simultaneously? -33.7 Your response differs from the correct answer by more than 100%. m/s (c) What was the velocity of each stone at the instant it hit the water? first stone -26.16 m/s -26.16 second stone Your response differs from the correct answer by more than 10%. Double check your calculations. m/s

Madison is standing by a window of her apartment. She sees a baseball passing upward by her window with a velocity of 14 m/s. If the ball was thrown by a person 18 m below on the street, what was the initial speed of the ball?