A 2000 kg truck is at rest at a stop sign. A 1100kg car collides head-on with the truck. The car was moving at 15.0m/s before the collision if the collision was completely inelastic, what is the velocity of the car and the truck after the collision?

I have never figured our why some teachers use the term "completeley" inelastic. Is that akin to being completely pregnant?

anyway, the collision is inelastic.
Momentum convervation: assume the car/truck are stuck.

2000*O+1100*15=(2200+11OO)V solve for V

To find the velocity of the car and the truck after the collision, we can use the principle of conservation of momentum. According to this principle, the total momentum before the collision is equal to the total momentum after the collision.

The momentum of an object is calculated by multiplying its mass by its velocity. The equation for momentum is:

Momentum = mass * velocity

Before the collision, the momentum of the car is given by:
Car momentum before = mass of car * velocity of car
= 1100 kg * 15.0 m/s

The momentum of the truck is zero since it is at rest:
Truck momentum before = mass of truck * 0 m/s
= 2000 kg * 0

After the collision, the car and the truck stick together and move with a common velocity. Let's call this final velocity "Vf".

The total momentum after the collision is the sum of the momenta of the car and the truck:
Total momentum after = (mass of car + mass of truck) * Vf

Using the principle of conservation of momentum, we can equate the total momentum before and after the collision:

Car momentum before + Truck momentum before = Total momentum after

(1100 kg * 15.0 m/s) + (2000 kg * 0) = (1100 kg + 2000 kg) * Vf

Simplifying the equation:

16500 kg⋅m/s = 3100 kg ⋅ Vf

Now, we can solve for Vf, the final velocity after the collision:

Vf = 16500 kg⋅m/s ÷ 3100 kg
Vf ≈ 5.32 m/s

Therefore, the velocity of the car and the truck after the collision is approximately 5.32 m/s.