Skateboarder Jake Brown plummeted to the floor so hard in the 2007 X Games his shoes flew off. Watch the video below to see what happened (and to get some insight from the newscasters.)
How many seconds did it take Mr. Brown to fall from his highest position until he just touched the floor?
What speed did he have on impact?
What total height did he fall?
How long did it take him to stop after he touched the floor?
What was his deceleration?
Ouch?
Watch the Blob Jump Official Guinness World Record video below. Disregard the horizontal motion (i.e., assume the blob jumper went straight up and then straight back down) and answer the following questions.
When did the blob jumper reach the highest point of the jump? How long did it take him to hit the lake surface after reaching the highest point of the jump? Use these numbers to answer the remaining parts of this problem.
How did his velocity on take off compare to his velocity on landing? Determine both velocities (their magnitudes and directions).
How high did he rise? Confirm or refute the claim that the jumper hit 17 m.
Fun?
homework
The diagram to the right shows a US one dollar bill held vertically above a person's hand with their finger and thumb arranged like they are ready to pinch something. Fingertip reaction time is about 200 ms for an average person. Show that it is unlikely that someone would be able to catch a US dollar bill in a situation like this if it was released without warning.
A ball is thrown straight up over level ground. State the direction of the velocity and acceleration of the ball after it has left the thrower's hand and is…
on the way up
at it highest point
on the way down
Whole body reaction time is about three-tenths of a second. Would you have enough time to throw yourself clear of a brick falling from a point 3 m directly overhead if you saw it the moment it came loose?
A basketball dropped from rest 1.00 m above the floor rebounds to a height of 0.67 m. Assuming the ball is not moving horizontally, calculate its velocity…
just before it hit the floor on the way down
just after it left the floor on the way up
If the ball is in contact with the floor for 0.10 s determine its acceleration…
