A ball with a mass of 2 kg is rolling at 6 m/s and elastically collides with a resting ball with a mass of 1 kg. What are the post-collision velocities of the balls?

1 Answer
ali ergin
Mar 1, 2016

v_1^'=2 m/s
v_2^'=8 m/s

Explanation:

vec P_1 + vec P_2= vec P_2^' + vec P_2^'" the conservation of momentum"
m_1*v_1+m_2*v_2=m_1*v_1^'+m_2*v_2^'
2*6+0=2*v_1^'+1*v_2^'
12=2*v_1^'+v_2^'" (1)"
v_1+v_1^'=v_2+v_2^'" (2)
6+v_1^'=0+v_2^'
v_2^'=6+v_1^'" (3)"
"use equation (1)"
12=2*v_1^'+6+v_1^'
12-6=3*v_1^2
6=3*v_1^' " " v_1^'=2 m/s
"use equation (3)"
v_2^'=6+2
v_2^'=8 m/s

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