2. 1D Motion / Kinematics

Vertical Motion and Free Fall

Open Question
A juggler throws a bowling pin straight up with an initial speed of 8.20 m/s. How much time elapses until the bowling pin returns to the juggler's hand?
Open Question
(b) If a flea can jump straight up to a height of 0.440 m, How long is it in the air?
Open Question
(a) If a flea can jump straight up to a height of 0.440 m, what is its initial speed as it leaves the ground?
Open Question
You throw a small rock straight up from the edge of a highway bridge that crosses a river. The rock passes you on its way down, 6.00 s after it was thrown. What is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? Ignore air resistance.
Open Question
You throw a glob of putty straight up toward the ceiling, which is 3.60 m above the point where the putty leaves your hand. The initial speed of the putty as it leaves your hand is 9.50 m/s. (b) How much time from when it leaves your hand does it take the putty to reach the ceiling?
Open Question
Nicole throws a ball straight up. Chad watches the ball from a window 5.0 m above the point where Nicole released it. The ball passes Chad on the way up, and it has a speed of 10 m/s as it passes him on the way back down. How fast did Nicole throw the ball?
Open Question
A typical laboratory centrifuge rotates at 4000 rpm. Test tubes have to be placed into a centrifuge very carefully because of the very large accelerations.b. For comparison, what is the magnitude of the acceleration a test tube would experience if dropped from a height of 1.0 m and stopped in a 1.0-ms-long encounter with a hard floor?
Open Question
A small rocket burns 0.0500 kg of fuel per second, ejecting it as a gas with a velocity relative to the rocket of magnitude 1600 m/s. (a) What is the thrust of the rocket?
Open Question
A small rocket burns 0.0500 kg of fuel per second, ejecting it as a gas with a velocity relative to the rocket of magnitude 1600 m/s. (b) Would the rocket operate in outer space where there is no atmosphere? If so, how would you steer it? Could you brake it?
Open Question
(I) A stone is dropped from the top of a cliff. It is seen to hit the ground below after 3.25 s. How high is the cliff?
Open Question
(II) Figure 2–42 shows the velocity of a train as a function of time.
(c) During what periods, if any, was the acceleration constant?
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Open Question
(II) A baseball is hit almost straight up into the air with a speed of 22 m/s. Estimate

(a) how high it goes, and
Open Question
(II) The best rebounders in basketball have a vertical leap (that is, the vertical movement of a fixed point on their body) of about 120 cm.

(b) How long are they in the air?
Open Question
(II) A baseball is seen to pass upward by a window with a vertical speed of 13 m/s. If the ball was thrown by a person 18 m below on the street,
(c) when was it thrown, and
Open Question
(II) Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 0.83 s after passing his window, 15 m above the sidewalk.

(b) Assuming the balloons are being released from rest, from what height are they being released?