Space Time & Motion A.2 Forces & Momentum (id: 04db56ea3)

本题目来源于试卷: Space Time & Motion A.2 Forces & Momentum，类别为 IB物理学

[单选题]
A roller coaster car of mass m approximates circular motion at point A as shown in the diagram.

The circular radius of the track curvature at point A is r and the track exerts a normal reaction force

$F_N$ on the cart.

Which expression gives the linear speed of the cart at point A?

A. 0
B. $\sqrt{2rg}$
C. $\sqrt{\frac{r(F_N-mg)}{m}}$
D. $\sqrt{\frac{r(mg-F_N)}{m}}$


参考答案:  D


本题详细解析:

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