A flat (unbanked) curve on a highway has a radius of 240.0m . A car rounds the curve at a speed of 22.0m/s
1. What is the minimum coefficient of friction that will prevent sliding?
2. Suppose the highway is icy and the coefficient of friction between the tires and pavement is only one-third what you found in part A. What should be the maximum speed of the car so it can round the curve safely?
friction
2012-10-13 10:31 pm
回答 (1)
2012-10-14 12:22 am
✔ 最佳答案
1. The centripetal force is provided by the frictional force.Hence, m.(22^2)/240 = u.(mg)
where m is the mass of the car, u is the coefficient of friction, and g is the acceleration due to gravity, taken to be 10 m/s^2.
i.e. u = 22^2/240g = 0.202
2. The coefficient of friction now becomes 0.202/3 = 0.0672
Max frictional force = 0.0672mg = 0.672m
Hence, mv^2/240 = 0.672m
where v is the max speed of the car to turn round the curve
i.e. v = 12.7 m/s
收錄日期: 2021-04-29 17:47:12
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