Three balls collide at the origin and stick together. Ball A is 4kg moving in +x direction at 3m/s towards the origin, Ball B is 6kg in + y towards origin at 5m/s and Ball C is 8kg, moving towards origin at an angle of 45 degrees from + x at 7m/s. What is the final velocity of the three balls after the collision?

Question

amistre64 · Answer

elastic versus inelastic collisions

amistre64 · Answer

$$m_1v_1+m_2v_2+m_3v_3=(m_1+m_2+m_3)v$$ http://www.batesville.k12.in.us/physics/apphynet/Dynamics/Collisions/inelastic_collisions.htm

amistre64 · Answer

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amistre64 · Answer

its prolly best to use cos and sin components of each force

amistre64 · Answer

bA; mv = 4(3) = 12 * cos(0) = 12

bB; mv = 6(5) = 30 * sin(90) = 30

bC; mv = -8(7) cos(45) = -28sqrt(2)
               -8(7) sin(45) = -28sqrt(2)

12+30-56sqrt(2)  is the what we have added altogether

divide this by: m1+m2+m3 to get the resulting velocity

$$\frac{12+30-56\sqrt{2}}{4+5+8+8}$$

since a split bC into 2 parts I assume we have to apply it as 2 parts as well

amistre64 · Answer

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maybe a better representation

if we go 12 over 30 up and diagonally 56  we calculate the distance from where we started .... but i cant say thats i good idea or not :)