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Kelvin Andersen
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Homework Statement
g = ##10m/s^2##
##\sqrt{3}## = 1.7
Determine work by the 20N force
Homework Equations
for an inclined plane:
W = ((F+mgsin30)-(mgcos30)μ)s -> (Fx-ff)*s
for object pulled with angle:
W= (Fcos60-(mg-Fsin60)μ)s -> (Fx-ff)*s
The Attempt at a Solution
W= ((Fcos60+mgsin30)-(mgcos30-Fsin60)μ)s
(W= (Fx-ff)*s, Fx=Fcos50+wsin30, ff=(wcos30-Fsin60)*μ)
What I did to get the equation above:
for Fx:
Based on inclined plane equation, Fx=F+wsin30
However, since F is angled, F becomes Fcos60
so Fx=Fcos60+wsin30
for ff:
Based on angled force equation, ff=w-sin60
I change w -> wcos30
so ff=wcos30-Fsin60
sin30=3/s -> s=6
W= (((20)(cos60)+(3)(10)(sin30))-((3)(10)(cos30)-(20)(sin60))(0.2))(6) (inputting number based on the above)
by using √3 = 1.7
W= ((10+15)-(25.5-17)(0.2))(6)
W= (25-1.7)(6) = 139.8 Joules (don't know if correct or not)
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