# physics

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Calculate the hang time of a person who moves horizontally 2.00 m during a 1.23 m high jump.

• physics -

The motion of jumping person is similar to projectile motion:
H=(Vo)^2•(sinα)^2/2g
L=(Vo)^2•(sin2α)/2g=
=(Vo)^2•(2sinα•cosα)/2g.

2H/L=sinα/cosα,

tanα=2H/L=21.23/2=1.23

α=arctan1.23=50.9°

Vo=sqr(2gH)/ sinα=6.33 m/s.
t=2Vo•sinα/g=1 s.

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