Recent content by carlitos_30

I can´t agree more. King book explains clearly and has a lot of programming exercises. K&R is just a reference manual IMO. Another good book is https://www.amazon.com/dp/1418835560/?tag=pfamazon01-20

Yes, outward the wrench due to Newton third law. May I conclude safely that the ridig body will keep rotating forever when only centripetal and the reaction to this force in the pivot(centrifugal?) are acting in the body?

Yes. To keep the wrench rotating or anything rotating with no friction, the 200 N force has to be applied every instant or only at the beginning?

Something like this: It will keep moving forever?

The center of mass would be at the center of the bar and I imagine is moving every instant, changing the velocity vector, hence there is an acceleration in the center of mass.

Moving at constant speed? In this example, a force is applied and the wrench start to move. When is moving, the 200 N force isn't applied any more? Is just applied at the beginning? Or I have to assume that the 200 N force is applied every instant the wrench is moving?

Justo imagine there is no Gravity or another force. Something like this: The dashes represent the bar. I----------------

Hello. Let's image a bar. In one side is attached to a body so the bar can rotate over this axis. There is no friction between the two bodies. The system is at rest in t=0. A force acts forming a 90° angle with the bar. The bar moves and begin to rotates. The force dissapear. There is no force...

Thanks both for your time and help.

I don´t see any reason of the WHY a positive charge generate an electric field outward the positive charge, except for a convention. If we assume that the electric field of a positive charge points inward and a negative charge points outward, it would be just the same as is assumed in the textbooks.

But, with a negative test charge, the electric field vector shoudn't point to the left?

Only if the test charge is positive. Why it can´t be negative? Just for convention?

But, the electric chage in a point in the plane: in the point there is no charge at all! So, how does the principle of equal charges applies here?

Hello. I have a doubt regarding the direccion of the electric field in a point from a source charges. Let be a charge in the left of the plane. In a point to the right of the charge, the direction of the electric field vector is to the right. If the charge is negative, the direction of the...

Sure not. The observer in the ground just can't note the ballast keep ascending because of the distance and he has no reference to compare the movement (the clouds are not good ones). An observer at the same level when the ballast is drop, would see the ballast ascending a little.