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Vanessa23
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Homework Statement
a ball started at a height of 12.5 meters and rolled to the edge of a roof which is at 7 meters. Using a^2+b^2=c^2 we know it rolled a distance of 8.14 meters on the roof because it rolled a horizontal distance of 6m and a vertical distance of 5.5m. Find the time it rolled down the roof. The roof makes a 40deg angle with the horizontal and coeff of friction is .388.
Homework Equations
Potential E=KE+Ffriction
mg*distance*sin(theta)=.5mv^2+(coeff of friction)*mgcos(theta)*distance down roof
acceleration=g*sin(theta)-g*(coeff. of friction)*cos(theta)
V=Vo+at
The Attempt at a Solution
8.14*g*sin(40)=.5v^2+.388*g*cos(40)*(8.14)
v=9.84m/s
a=g*sin40)-g*.388cos(40)
a=3.39m/s^2
9.84=3.39t
t=2.90 seconds
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