[zcarfaz]

Please help me with the following question and please explain the reasons for the answers Just the answers wouldn't help me a lot... Thank you!!

1) A cannon ball is fired at an angle of 45 degrees What of the following is/are conserved?
a) Kinetic Energy
b) Total Energy
c) Total Momentum
d) Horizontal Momentum
e) Vertical Momentum

2) A sphere, disk and a hoop are about to roll down three identical inclined planes. Which one will reach the bottom first?
What matter the results? Radius, mass or both?

[zcarfaz]

My main problem...

A particle is moving in circular motion and it is decreasing its speed. How would the tangential velocity, angular velocity, linear velocity, centripetal acceleration and centripetal force of the particle show up in a vector diagram?

Sub questions...
I know centripetal force is acting towards the center and tangential velocity is tangential to the path of the particle but I don't know the rest, does the fact the particle decreasing velocity has an effect(especially for centripetal acceleration) .

The fact that the motion is horizontal or vertical has an effect please explain...

Thank you!!

[zcarfaz]

A uniform rod is fixed to a wall from the center so it can rotates. Two masses (m1 and m2) with velocity v1 and v2 come from the opposite sides and hit the ends of the rod( m1 comes from the top and hit the left end. m2 comes from the bottom and hit the right end) after the collision how do I find the angular speed of the rod?
Thank you!