physic hw momentum?

Question

A .3-kg puck, initially at rest on a frictionless horizontal surface, is struck by a .2-kg puck that is initially moving along the x-axis witha a velocity of 2m/s. After the collision, the .2-kg puck has a speed of 1 m/s at an angle of Θ53 degrees to the positive x-axis. (a)Determine the velocity of the .3-kg puck after the collision. (b) Find the fraction of kinetic energy lost in the collision.

how do u solve it

Answer 1

First, you look at conservation of momentum in the x and y since the center of mass velocity is constant through the collision.

Next, you compare starting KE with ending KE.

X first:
0.2*2=0.2*1*cos(53)+0.3*cos(θ)*v

Now Y
0=0.2*1*sin(53)-0.3*sin(θ)*v

the negative sign is not necessary, but since I know the angle is below the horizontal, it makes the algebra easier.

Solve for v and θ

I find solving for tan(θ) to be the easiest approach:
0.2*1*sin(53)=0.3*sin(θ)*v
0.2*(2-cos(53))=0.3*cos(θ)*v
divide to get
sin(53)/(2-cos(53))=tan(θ)


j

Answer 2

properly what you opt to think of approximately is whether or no longer or no longer there is a few non-conservative rigidity appearing on the item. Like huge style a million isn't preserving momentum because of the fact there is an exterior rigidity being utilized (the breaking rigidity for this reason). 2. particular. Frictionless so no non-conservative exterior forces. 3. i think of you are able to argue particular. If pi = pf (m1v1i + m2v2i) = (m1v1f + m2v2f) Mass one is almost negligible while in comparison with an vast wall. And vi and vf for wall = 0 (m1v1 + 0) = (m1v1f + m2v2f) So i assume technically particular because of the fact no exterior non conservative forces, whether i think of its arbitrary and additionally you will argue the two way. yet i might positioned particular