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killaI9BI
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Homework Statement
Two boys have a "hang time" contest on their skateboards. At a speed of 5.0 m/s, they both jump straight up and then land on their moving skateboards. The first boy goes a horizontal distance of 7.5 m before he lands, while the second boy goes 6.0 m before he lands.
a) How long was each boy in the air
b) How high did each boy jump? (Hint: Separate the horizontal and vertical motions. Time is the same for both)
Homework Equations
d = vi X t + 1/2a X t2
The Attempt at a Solution
a) first boy: 7.5/5 = 1.5 s
second boy: 6/5 = 1.2 s
b)
d = 5 X 1.5 + ½(-9.8) X 1.52
d = 7.5 + (-3775)
d = 3.725 m
d = 5 X 1.2 + ½(-9.8) X 1.22
d = 6 + (-7.056)
d = (-1.056) m
I don't know if I'm using the wrong formula or a wrong value... possibly because I calculated the answer to the first question incorrectly?