# Momentum/Impulse [Final Velocity]

#### silverduelist

1. Homework Statement
"A truck weighs four times as much as a car, If the truck coasts into the car at 12 km/h and they stick together, what is their final velocity."

2. Homework Equations
Change in momentum a = change in momentum b
OR
m1v1 = m2v2
OR
(delta)P system = 0

3. The Attempt at a Solution
I HAVE NO IDEA. SRSLY.

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#### Hootenanny

Staff Emeritus
Gold Member
1. Homework Statement
"A truck weighs four times as much as a car, If the truck coasts into the car at 12 km/h and they stick together, what is their final velocity."

2. Homework Equations
Change in momentum a = change in momentum b
OR
m1v1 = m2v2
OR
(delta)P system = 0

3. The Attempt at a Solution
I HAVE NO IDEA. SRSLY.
Welcome to Physics forums.

As you have correctly surmised, momentum is conserved in this case (since there are no net external forces acting). All three of your relevant equations are equivalent, so how about trying to apply one of them to this problem?

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