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JetGot 發問於 科學及數學其他 - 科學 · 1 十年前

uniform circular motion

Motorcyclists lean inwards while turning around a corner. The higher their speeds, the closer they lean to the ground. Explain the phenomena briefly.

DO NOT JUST GIVE ME THE ANSWER (Aviod the overturning)!!!!! Explain!!!!!!!!!!

1 個解答

• cipker
Lv 5
1 十年前
最愛解答

The reason for tilting in wards is to allow the normal reaction by the ground to exert a torque about the CG to balance the torque by friction. This keeps the motorcycle in equilibrium and avoids overturning. From the equation (tan phi = v^2/gr), we see that the angle increases with speed. Qualitatively, if the speed increases, the magnitude of friction will increase as to provide a larger centripetal force required for turning. The increase in friction causes an increase in torque due to the friction about CG. This increase in torque must be balanced by the additional torque due to reaction to avoid overturning. Since reaction equals mg, the only way to increase the moment is to increase the moment arm about CG, i.e. the dtriver leans inwards.

2010-07-24 21:09:20 補充：

This keeps the motorcycle in ROTATIONAL equilibrium and avoids overturning.