Unformatted text preview: wheel to prevent slippage! What do I need to do now? If slips, we know the friction force. What is it? F A = μ k N A = 0.25 N A (1) (2) (3) Now have 4 eq, 4 unknowns. Solve it Solving for the unknowns yields: N A = 50.0 lb F A = 0.25 N A = 12.5 lb α = 25.5 rad/s 2 a G = 8.05 ft/s 2 (4) How would you find the acceleration of point A (touching the surface)? 2 / / ϖ α G A G A G A r r a a A A A A A× + = Problem Type: Find: Given: k G = 0.7 ft, W = 50 lb, μ k = 0.25, μ s = 0.3, M = 35 ftlbs a G Reflection: Need to be very careful with signs when considering rolling kinetics. Also when friction is involved you must check whether there is slip or not as two separate cases. This has implications for all types of vehicles from bicycles to race cars! EX22.2 – Rolling Wheel on Flat Surface...
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 Spring '05
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 Acceleration, flat surface, 8.05 ft, 12.5 lb

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