Two masses m1 m and m2 m5 undergo an elastic collision in

Two masses m_1 = m and m_2 = m/5 undergo an elastic collision in 1 dimension, m1 is moving to the right with a speed of 10 m/s, m2 is moving to the left with a speed 25 m/s. After the collision ml has a speed of 5 m/s to the left, what is the speed and direction of m2?

Solution

mass of m1 = m

initial Velocity of m1 = 10

final velocity of m1=-5

mass of m2 = m/5

initial velocity of m2 = -25

final velocity of m2 =??

using conservation of momentum

m1v1+m2v2= m1v1\' +m2v2\'

m*10 +m/5*-25 =m*-5 + m/5 *v2\'

v2\' = (10-5+5)*5 =50 m/s