A cart with mass 340 g moving on a frictionless linear air track at an initial speed of 1.2 m/s undergoes an elastic collision with an initially stationary cart of unknown mass. After the collision, the first cart continues in its original direction at 0.66 m/s.
(a) What is the mass of the second cart?
(b) What is its speed after impact?
(c) What is the speed of the two-cart center of mass?
I'll use this space to organize variables:
m1 = 0.34 [kg]
v1i = 1.2 [m/s]
v1f = 0.66 [m/s]
The Attempt at a Solution
Okay using the Conservation of Momentum model, I have:
m1v1i = m1v1f + m2v2f
So in order to find the mass of the second cart, I have:
(m1(v1i - v1f))/v2f = m2
And now I'm stuck because I don't have the final velocity of the second cart in order to compute its mass.