How fast must a 3000 lb car be traveling to hit a 4000 lb minivan on the side rear to spin it 180°

at what angle? what's the friction?

It appears to be at a 45° angle , minivan is hit on rear right wheel and top of the line Mercedes Benz front airbags deploy.

If you are looking for "expert scientific testimony" to support a court case, you have come to the wrong place.

Not at all, my dad was involved in the accident. And no one was hurt, insurance info was exchanged and parties went home uncited. I'm just fascinated by the forces involved and very curious as to the physics causing the spinning effect . My dad says the Mercedes weighs as much as the van or even more. Thanks anyways.

To determine how fast the 3000 lb car must be traveling to hit the 4000 lb minivan on the side rear and spin it 180°, we need to use the principles of linear momentum and conservation of energy.

First, let's break down the problem into a few steps:

Step 1: Calculate the momentum of the two vehicles before the collision:
- Momentum (p) is equal to the mass (m) multiplied by the velocity (v).
- The momentum of the car (C) before the collision is: pC = mC * vC
- The momentum of the minivan (M) before the collision is: pM = mM * vM

Step 2: Apply the conservation of linear momentum principle:
- The total momentum after the collision should be equal to the total momentum before the collision.
- Therefore, pC + pM = p'C + p'M, where p' represents the momentum after the collision.

Step 3: Consider the effect of the collision on the minivan:
- We know that the minivan needs to be spun 180° after the collision.
- To achieve this, a significant amount of angular momentum is required, which would come from the linear momentum of the car.

Step 4: Determine the velocity needed to achieve the spin:
- Assuming the spin is instant and occurs at the moment of impact, we need to calculate the minimum velocity of the car to transfer enough linear momentum to create the desired angular momentum in the minivan.

The specific steps and calculations to determine the exact velocity required involve more complex physics equations. It involves considering the lever arm distance, rotational inertia of the minivan, transfer of linear momentum into angular momentum, and the conservation of energy during a collision.

It's important to note that obtaining the accurate answer to this question would require more detailed information, such as the distance between the vehicles at the moment of impact and the coefficient of friction between the tires and the ground.

Given the complexity of the calculations involved and the lack of specific information to provide a precise answer, it may be best to leave these calculations to experts in the field, such as accident reconstruction specialists or physicists who specialize in collision dynamics and impact analysis.