Pytanie: Dave Johnson, the bronze medalist at the 1992 Olympic decathlon in Barcelona...?

( Wstecz )

Answer #1:

We can find this using one of the four kinematic equations of motion in the vertical direction. Note that when he is at his highest point, his centre of mass will have stopped going up but not yet started falling back down, so his vertical velocity will be zero at his highest point.

We have the following information (either implicitly or explicitly):
u = initial velocity = 5.35 m/s
v = final velocity = 0 m/s
a = acceleration (due to gravity) = -9.8 m/s²
d = distance = ?

v² = u² + 2ad. We must rearrange to make d the subject: Since v=0, we have

d = -u²/2a = -5.35²/-19.6 = 1.46 m.





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