4 ms·

Look at the stopping distances, it's affected by mass F = ma here. The a part is affected by the quality of the tires/breaks/suspension... but that's getting i

Look at the stopping distances, it's affected by mass F = ma here. The a part is affected by the quality of the tires/breaks/suspension... but that's getting into specifics that don't really fit the generality of the fleet of vehicles getting larger and heavier and their variety in qualities will more time to avoid an accident that they may not have.

giantg2 5y ago
I've never seen stopping distance noted that way. Looks more like force? If you aren't changing other characteristics, then yes increasing mass will increase stopping distance. The problem with this assumption is that things like friction coefficient usually change when you are changing mass (tire size is an obvious one). Most new vehicles stop 60-0 between 120-140 feet. There are heavier vehicles that stop shorter than lighter vehicles. I'm just saying it's not always that vehicles are heavy. The primary variable here (in applied stopping distance) is speed due to the simple fact that reaction time is the same and you are covering distance during that lag, plus velocity is an exponential effect. Here's a good resource. https://byjus.com/stopping-distance-formula/ https://byjus.com/stopping-distance-formula/
bradlys 5y ago
Heavier car doesn’t mean it can’t stop well. If the larger car also has a larger tire contact patch and larger brakes, it can stop just as fast as the smaller vehicle. This shown by many performance SUVs and various other vehicles that weigh in 5000lb+ but somehow come to a stop about as fast as their 3000lb counterparts. Consider the Tesla model s plaid - it has a super fast acceleration rate yet is also stupid heavy. If it can accelerate super fast - it can also stop super fast because the tires work well in either direction. I’ve watched enough brake tests of cars to see this pan out. It’s all about the tires and brakes. Weight doesn’t matter that much when the manufacturer accounts for it.

giantg2 5y ago

I've never seen stopping distance noted that way. Looks more like force? If you aren't changing other characteristics, then yes increasing mass will increase stopping distance. The problem with this assumption is that things like friction coefficient usually change when you are changing mass (tire size is an obvious one). Most new vehicles stop 60-0 between 120-140 feet. There are heavier vehicles that stop shorter than lighter vehicles. I'm just saying it's not always that vehicles are heavy. The primary variable here (in applied stopping distance) is speed due to the simple fact that reaction time is the same and you are covering distance during that lag, plus velocity is an exponential effect. Here's a good resource. https://byjus.com/stopping-distance-formula/ https://byjus.com/stopping-distance-formula/

bradlys 5y ago

Heavier car doesn’t mean it can’t stop well. If the larger car also has a larger tire contact patch and larger brakes, it can stop just as fast as the smaller vehicle. This shown by many performance SUVs and various other vehicles that weigh in 5000lb+ but somehow come to a stop about as fast as their 3000lb counterparts. Consider the Tesla model s plaid - it has a super fast acceleration rate yet is also stupid heavy. If it can accelerate super fast - it can also stop super fast because the tires work well in either direction. I’ve watched enough brake tests of cars to see this pan out. It’s all about the tires and brakes. Weight doesn’t matter that much when the manufacturer accounts for it.