**Answer:**

<em>The green car had the greatest momentum</em>

**Explanation:**

<u>Momentum</u>

Momentum can be defined as "mass in motion" and is calculated as the product of the mass of the object by its velocity.

Being v the magnitude of the velocity and m the mass of the object, the momentum is calculated with:

p = mv

The green car had a mass of m1=1200 kg and crossed the finish line at v1=53 m/s. Hence, its momentum was:

p1 = 1200 Kg * 53 m/s = 63600 Kg.m/s

The red car had a mass of m2=1100 kg and crossed the finish line at v2=55 m/s. Hence, its momentum was:

p2 = 1100 Kg * 55 m/s = 60500 Kg.m/s

Since p1 > p2, then **the green car had the greatest momentum**