An elastic collision occurs between two cars. Car A, with mass 340 kg, is moving at -2.4 m/s. Car B is initially at rest. After collision, Car A moves at -0.8 m/s and Car B moves at -V. Calculate the

The principle illustrated is the Principle of Conservation of Linear Momentum.
Statement: In an isolated system, the total linear momentum remains constant.

This is an elastic collision, so both linear momentum and kinetic energy are conserved.
Let Asisipho and her car be object 1, and Ziphokazi and her car be object 2.
Let the direction to the left be negative.

Given:
Mass of Asisipho and her car, $m_1 = 340$ kg
Initial velocity of Asisipho, $v_{1i} = -2.4$ m/s
Initial velocity of Ziphokazi, $v_{2i} = 0$ m/s
Final velocity of Asisipho, $v_{1f} = -0.8$ m/s
Final velocity of Ziphokazi, $v_{2f} = -V$ (where V is the magnitude of Ziphokazi's velocity)
Mass of Ziphokazi and her car, $m_2 = ?$

Using the principle of conservation of linear momentum:

For an elastic collision, the relative speed of approach equals the relative speed of separation:

Now substitute the value of $V$ into Equation 1:

The combined mass of Ziphokazi and her car is $\text{170 kg}$.