So there is no force along the arc, but there must be a normal force.

所以在弧线上没有力，但是肯定存在法向力。

youdao

When the British Labour Force Survey asks people whether they are depressed, the U-bend becomes an arc, peaking at 46.

当英国劳动力调查询问人们是否郁闷时，U型变成拱型，在46岁时达到顶点。

youdao

Big lifting force and wide lifting height adjustment, especially suitable for matching work with submerged arc stud welding machine.

提升力大，提升高度调节范围广，特别适合与埋弧螺柱焊机配套使用。

youdao

For in Egypt, it was the moral force of nonviolence -- not terrorism, not mindless killing -- but nonviolence, moral force that bent the arc of history toward justice once more.

WHITEHOUSE: President Obama on a Historic Day in Egypt