When does friction in a car becomes positive?

AI Thread Summary
Friction in a car is defined by its direction relative to a chosen coordinate system, making the terms "positive" and "negative" arbitrary. The concept of positive friction arises when the frictional force aligns with the defined positive direction of motion. On dry surfaces, friction typically aids in acceleration, while on wet surfaces and ice, it can become insufficient for maintaining control. Understanding the proper setup of coordinate axes is crucial for accurately analyzing frictional forces. Clarifying these concepts can resolve confusion regarding when friction is considered positive.
chronocross_xp
Messages
1
Reaction score
0
when does friction in a car becomes positive? in a dry surface and i na wet surface and on ice.
 
Physics news on Phys.org
chronocross_xp said:
when does friction in a car becomes positive? in a dry surface and i na wet surface and on ice.

You should know why this question doesn't make sense. What you call "positive" and "negative" are really arbitrary. It is in reference to the coordinate axis that YOU (or anyone else) set up. If the frictional force happens to be in the same direction as what you call "positive x-axis", for example, then it is positive!

Maybe, indirectly, the proper setting up of coordinate axis could be the source of your problem. I would recommend looking at one of the tutorials that we have on here to see if this is something you should understand first.

Zz.
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Friction direction change in a inclined circular bend (car on a road)
Replies
11
Views
1K
Is the work done by friction on a moving car's wheel positive or negative?
Replies
7
Views
2K
Irodov- 1.123- Simple conceptual question with two masses connected by a spring
Replies
20
Views
631
Distance travelled by a car considering only air friction?
Replies
4
Views
2K
Friction Forces on 2WD vs 4WD Vehicles
Replies
6
Views
1K
Final Velocity of a car with a opposing decreasing drag force
2
Replies
57
Views
2K
Car turning and centripetal force
Replies
18
Views
3K
Questions on Wheels: Reduce Friction & Traction
Replies
7
Views
1K
Problem with the power of car
Replies
3
Views
864
Car that undergoes non-uniform circular motion
Replies
1
Views
1K

Hot Threads

Recent Insights

Back
Top