Wednesday, January 27, 2010

Circular Motion and Gravitation

I learned a couple of things about circular motion and gravitation. I learned that when an object moves in a vertical circle at the end of a string its tension in the string will vary with its position. The centripetal force on an object at any point is the vector sum of FT and the component of the object's weight toward the center of the circle. I learned that gravitation is a force that varies with the square of the distance between to objects and that every object attracts every other object.

I didn't find too many things hard. I mainly had problems figuring out how to draw the FBD for the circular motion problems, and I still struggle a little bit with problems using trigonometry.

I have gotten better at remembering formulas, but I’m still not too good at good at FBDs. Some problems are worded a little odd, and that sometimes confuses me.

Sunday, January 10, 2010

Newton's Second Law of Motion

I learned many things about Newton's Second Law. I learned that an object's velocity will change if it is pusshed or pulled by another object. I didn't find too much dificulty with this section because of the stuff we had learned earlier was very similar. Finding friction was something that was a little hard at first but then I found it quite easy. I just had to do a ∑Fx=... , and once I figured out how to do that it became very easy. But, the only thing that was a little difficult were solving for forces at an angle, I still get confused a bit about when to use cos or sin. I think I need to work better on solving things at an angle. I am pretty good at finding any other forces.

(Sorry for posting about an hour later, I have internet problems at the wort of times.)