A stand shows a pendulum in 5 positions. A has the pendulum bob at a 45 degree angle to the left. C has the pendulum bob straight down, and B is halfway between A and C. E is has the pendulum bob at a 45 degree angle to the right, and D is halfway between C and E.
Determine how potential and kinetic energy changes at each position of the pendulum as the ball swings from A to E.

Position A:

Position B:

Position C:

Position D:

Position E:

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.

On a horizontal frictionless surface, a small block with mass 0.200 kg has a collision with a block of mass 0.400 kg. immediately after the collision, the 0.200 kg block is moving at 12.0 m/s in the direction 30° north of east and the 0.400 kg block is moving at 11.2 m/s in the direction 53.1° south of east. use coordinates where the +x-axis is east and the +y-axis is north.(a) what is the total kinetic energy of the two blocks after the collision (in ) what is the x-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your ) what is the y-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your answer.)

What practical value did astronomy offer to ancient civilizations?