# Recent content by Petrulis

1. ### Resistance of a circuit

Pleas someone have a look at this problem. It is very important for me.
2. ### Resistance of a circuit

Homework Statement First of all, there is an an attachment called EXPLANATION which shows the situation and what I have done so far. So we have got some circuits which are made of triangles (each triangle is made of three resistors (resistors here are shown as rectangles)). The resistance...
3. ### Potentials of the points in the electrical circuit

Please somebody help me with this problem. I just need some resources which I could use for learning.
4. ### Potentials of the points in the electrical circuit

Thanks for answers. I was really talking about a little bit different way for solving this kind of problems. For example, please have a look at this picture: http://img340.imageshack.us/my.php?image=copyofhexaoe6.jpg Hexagonal circuit has got a vertical symmetry axis, so the...
5. ### Potentials of the points in the electrical circuit

Homework Statement So, first of all, here is a drawing of a circuit: http://img253.imageshack.us/my.php?image=hexabj4.jpg The resistance of each hexagon wire is r. I need to find the resistance of this circuit when it is connected to the source with points A and B. I know that in...
6. ### Pressure problem

Homework Statement First here's the drawing which shows the situation: http://img81.imageshack.us/my.php?image=phyxt3.jpg So there is 1 metre length and 2 millimetres diameter glass pipe which is bent. The angle ABC is equal to 90 degrees. The part of the pipe ADB is horizontal and the...
7. ### Oscillation problem

Homework Statement A spring (which tension is k) is connected with a body (which mass is m). The whole system is in viscous liquid. In this liquid frictional force is proportional to speed: F = -C*v. With what C value the oscillation won't happen? The Attempt at a Solution The...
8. ### Energy conservation law problem

Homework Statement There is a ring which radius is R. A little ball moves inside this ring. Ring's plane is perpendicular to the surface of ground. When a ball is moving inside a ring (ring is in quiet), the ball reaches a height which is equal to R/2. The ring starts to move upright with a...
9. ### Energy and momentum conservation laws problem

Homework Statement Two balls go vis-a-vis (each of them speed is v) and strike. Hit is absolutely elastic. After the hit, one of the balls changes his motion direction 30 degrees. I need to find the direction of the other ball and both ball speeds after the hit. The Attempt at a Solution...
10. ### Energy conservation law problem

Thanks for explanation. But could anyone give a suggestion about counting horizontal component of the ball's acceleration. And I have no idea how this tangential acceleration interrelates with centripetal acceleration.
11. ### Momentum conservation law in shooting gun problem

Thanks for help. But if I just use the acceleration equation and multiply it by the mass of the bullet, I get the answer: mv^2/(2*l). And in my solution there is an answer mv^2/(4*l), so twice less. I think that this happens because the speed of the bullet is not steady. So the recoil force is...
12. ### Momentum conservation law in shooting gun problem

Homework Statement There is a gun which mass is M = 4 kg. The length of the gun's barrel is l = 50 cm. I need to find the average recoil force while shooting the bullet which mass is m = 5g. The speed of bullet when it leaves the gun's barrel is v = 930 m/s. The Attempt at a Solution...
13. ### Problem with corservation laws

Please somebody have a look :)
14. ### Problem with corservation laws

Homework Statement Here is the drawing which shows the situation: http://img260.imageshack.us/my.php?image=monkeygn4.jpg The disc is weightless. There is a rope which is rolled over the disc. A monkey is fastened at the point A. At the point B there is a body bound to rope. The mass of...
15. ### Pendulum physics problem

Homework Statement Mass m ball hangs on the L length thread. This system is turned up by angle alfa from the vertical. What is the stretch force when the ball passes the state of balance (where ball's kinetic energy is the biggest)? The Attempt at a Solution At the alpha position...