1)It will take less energy to stop a car moving 30 kmh than
60 kmh. the momentum of the car moving with greater velocity will require
greater force to stop it. And more forces of inertia will also be acting on it.
2)same principle apply here as well. A car with more mass is
moving with greater momentum even though the velocity may be same.
3)it is advised to enter a curve at its edges. As the
centrifugal force required to keep the car in the arc and from flipping over
will be least.
4) it depends on the nature of crash. And the angle at which
the force acted on the car and subsequently on the passenger. A side on
collsion means there is less distance between the object hitting the car and
the passenger. That means the car has a less chance of absorbing the force and
the passenger is subject to a greater force.
