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PE and KE of a water balloon

  • #1
265
0
A prankster drops a water balloon from the top of a building on an unsuspecting person on the sidewalk below. If the balloon is traveling at 30.3m/s when it strikes a person's head ( 1.5m above ground). How tall is the building? Neglect air resistance.

PE= KE
mgh=.5*mv^2
h= v^2/2g
h=(30.3m/s)^2/(2*9.81m/s/s)
h=918.09 m^2/s^2 / 19.62 m/s/s
h= 46.8m

total height = 1.5m + 46.8m = 48.3m
is this right? Is the sig figs right?

Thank you
 

Answers and Replies

  • #2
458
0
Looks right.
 
  • #3
335
0
easy.
 

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