2个物理题,帮忙做算下.最好用英文1.Twoidenticaltinyspherescarryingthesamechargeare1.0mapartcentertocenterinvacuumandexperienceanelectricalrepulsionof1N.Whatistheircharge?2.Findtheratiooftheelectrostaticand

Question

2个物理题,帮忙做算下.最好用英文
1.Two identical tiny spheres carrying the same charge are 1.0 m apart center to center in vacuum and experience an electrical repulsion of 1N.What is their charge?
2.Find the ratio of the electrostatic and the gravitational forces between two electrons when they are 1 m apart.
不是要翻译啊
是要回答

Answer 1

1.F=k*Qq/R^2 => 1=9*10^(-9)*q^2/1^2 [identical的意思是完全相等的.之后把q求出来就是电量了.而且要注意,repulsion是互相排斥,就是说带得同种电荷.]
2.上面求得是electrostatic force,要求gravitational force,就用 F=G*Mm/R^2 [因为两个球完全一样,所以也可以把Mm写成m^2.之后带入就行了,唯一不知道的就是质量,题中应该给了吧?止后求出的两个力再除一下,就是比率（ratio）.]