You run straight off a high diving board at a speed of 6 m/sec. You hit
the water 2 seconds later.
a. How far did you travel horizontally during the 2 seconds?
b. How far did you travel vertically during the 2 seconds?
c. How fast were you moving horizontally when you hit the water?
d. How fast were you moving vertically when you hit the water?



Answer :

AL2006


a). Your horizontal speed doesn't change. 
Your horizontal distance is . . .

         (speed) x (time) = ( 6 m/s ) x ( 2s ) = 12 meters .
  ====================================
b). Your vertical motion is accelerated because of gravity.
Your vertical distance is . . .

  (original vertical speed x time) + (1/2) (acceleration of gravity) (time)²

  =      ( 0 )                          + (1/2) (9.81) (2)²

  =      4.905 x 4  =  19.62 meters  (a very high diving board indeed, like 64-ft !)
  ====================================
c). Your horizontal speed doesn't change. 
It's still 6 m/s when you splash down.
  ====================================
d). Your vertical speed grows steadily, because of gravity.
It becomes 9.81 m/s greater every second.

After 2 seconds, your vertical speed is (2 s) x (9.81 m/s²) = 19.62 m/s downward


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