Difference between a Volkswagen and tractor trailer that negotiate a curve

Question

Certain road signs specify safe speeds around curves. I know that the mass of the object does not matter. How can a Volkswagen negotiate certain curves at the safe speed of 40 mph, yet a tractor trailer can't safely negotiate this curve at this speed?

Thanks for any help! =)

Answer 1

It's about the height of the CG relative to the left-right separation of the wheels. Rollover occurs when the resultant of the vertical gravitational acceleration and the lateral acceleration, drawn from the CG, lies outside the tires. The lateral acceleration at rollover therefore = g * 0.5sep/CG height. A typical loaded tractor trailer might have the CG 10 ft off the ground and 8 ft wheel separation allowing 0.4 g lateral acceleration, while the VW might be closer to 3 ft CG height and 4.5 ft separation allowing 0.75 g lateral acceleration.

Answer 2

The center of mass for the tractor trailer is higher in proportion to its width.

Answer 3

Firstly i would say the mass of the objects matters a lot. it has more momentum that way and momentum is a vector meaning it will needs a force to change it's direction. more momentum, more force needed.

Secondly it will also depend upon how much grip each vehicle has which will mainly depend on their tires and their cross section with the road surfave.

So for example if you had a VW and a tractor that had the same tires( all evenly distributed with same friction force etc) but the tractor was heavier then it would turn slower.

Also if they weighed the same but the trailer had 2 small wheels it would turn slower