Answer:
Step-by-step explanation:
It is possible that after an elastic collision a moving mass (1) strikes a stationary mass (2) and the two objects will have exactly the same final speed.
During an elastic collision, the momentum and kinetic energy are both conserved.<em> Since one of the object is a stationary object, its velocity will be zero hence the other moving object will collide with the stationary object and cause both of them to move with a common velocity.</em> The expression for their common velocity can be derived using the law of conservation of energy.
<em>Law of conservation of energy states that the sum of momentum of bodies before collision is equal to the sum of momentum of the bodies after collision.</em>
Since momentum = mass*velocity
<u>Before collision</u>
Momentum of body of mass m1 and velocity u1 = m1u1
Momentum of body of mass m2 and velocity u2 = m2u2
<em>Since the second body is stationary, u2 = 0m/s</em>
Momentum of body of mass m2 and velocity u2 = m1(0) = 0kgm/s
Sum of their momentum before collision = m1u1+0 = m1u1 ... 1
<u>After collision</u>
Momentum of body of mass m1 and velocity vf = m1vf
Momentum of body of mass m2 and velocity vf = m2vf
vf is their common velocity.
Sum of their momentum before collision = m1vf+m2vf ... 2
Equating 1 and 2 according to the law;
m1u1 = m1vf+m2vf
m1u1 = (m1+m2)vf
vf = m1u1/m1+m2
<em>vf s their common velocity after collision. This shows that there is possibility that they have the same velocity after collision.</em>