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posted by  zaachary on 11/7/2009 9:35:52 AM  |  status: Closed  |  Earned Karma: 38

Finding Velocity - WILL RATE HIGHEST RATING

Course Textbook Chapter Problem Needs by
Algebra Based Physics N/A N/A N/A 11/7/2009 at 9:00:00 AM
Question Details:
A 20.4-kg boy slides down a playground slide that drops through a height of 2.15 m. If the boy starts at rest at the top of the slide and the slide does a nonconservative work of -363 J on the boy on the way down, what is the boy's speed at the bottom of the slide?
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posted by D.J84 (MNK) on 11/7/2009 9:42:40 AM  |  status: Live
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Response Details:
initial kinetic energy of the boy=0
initial potential energy of the boy=m*g*h=20.4*9.8*2.15=429.83 J

final potential energy=0
let the velocity of boy at the bottom of the slide=v m/s

according to conservation of energy
(1/2)*20.4*v2+363=429.83
v=2.56 m/s (ans)
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