Reed S. answered • 09/26/24
a) Why vehicles overturn: Vehicles overturn when going too fast around a curve because the force of friction between the tires and the road creates a torque around the center of mass (CM) of the vehicle.
This torque exists because the center of mass of a vehicle is above the ground, but the force of friction from the tires is on the ground and runs parallel to the ground. Therefore there is a moment arm between the CM and the force of friction from the tires.
During normal driving, this torque is not strong enough to flip the vehicle over. However, in vehicles with a high enough CM and grippy enough tires, this can cause a roll-over.
b) Which wheel leaves the ground first: The inner wheels leave the ground first. (i.e. the left wheels during a left turn or the right wheels during a right turn). Imagine a car driving away from you and turning to the left but not travelling fast enough to flip. As you have probably seen in real life, the left turn will cause the car to lean in the clockwise direction. Now imagine that the car does flip. The car will keep leaning in the clockwise direction, so the left wheels will have to lift off the ground as the car rotates until it eventually rolls over.
If the car turns to the right, the same leaning process will occur, but this time in the counterclockwise direction. Therefore, the right wheels will lift first.
