the knowns in this problem. (b) How high does his body rise above the water? To solve this part, first
note that the final velocity is now a known and identify its value. Then identify the unknown, and
discuss how you chose the appropriate equation to solve for it. After choosing the equation, show
your steps in solving for the unknown, checking units, and discuss whether the answer is
reasonable. (c) How long is the dolphin in the air? Neglect any effects due to his size or orientation.
. A swimmer bounces straight up from a diving board and falls feet first into a pool. She starts
with a velocity of 4.00 m/s, and her takeoff point is 1.80 m above the pool. (a) How long are her feet
in the air? (b) What is her highest point above the board? (c) What is her velocity when her feet hit
. (a) Calculate the height of a cliff if it takes 2.35 s for a rock to hit the ground when it is thrown
straight up from the cliff with an initial velocity of 8.00 m/s. (b) How long would it take to reach the
ground if it is thrown straight down with the same speed?
. A very strong, but inept, shot putter puts the shot straight up vertically with an initial velocity of
11.0 m/s. How long does he have to get out of the way if the shot was released at a height of 2.20
m, and he is 1.80 m tall?
. You throw a ball straight up with an initial velocity of 15.0 m/s. It passes a tree branch on the
way up at a height of 7.00 m. How much additional time will pass before the ball passes the tree
branch on the way back down?
. A kangaroo can jump over an object 2.50 m high. (a) Calculate its vertical speed when it leaves
the ground. (b) How long is it in the air?
. Standing at the base of one of the cliffs of Mt. Arapiles in Victoria, Australia, a hiker hears a rock
break loose from a height of 105 m. He can’t see the rock right away but then does, 1.50 s later. (a)
How far above the hiker is the rock when he can see it? (b) How much time does he have to move
before the rock hits his head?
. An object is dropped from a height of 75.0 m above ground level. (a) Determine the distance
traveled during the first second. (b) Determine the final velocity at which the object hits the ground.
(c) Determine the distance traveled during the last second of motion before hitting the ground.
. There is a 250-m-high cliff at Half Dome in Yosemite National Park in California. Suppose a