Normal Reaction Forces on a Moving Car

  • Thread starter Thread starter wai1997401
  • Start date Start date
  • Tags Tags
    Car Forces
Click For Summary

Homework Help Overview

The discussion revolves around the normal reaction forces acting on a car's wheels during acceleration. The original poster is trying to understand how these forces change when the car begins to accelerate, particularly focusing on the rear wheel's normal reaction force.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between normal reaction forces and acceleration, with some questioning the original poster's understanding of how these forces behave. There are suggestions to draw free body diagrams and consider the effects of friction and torque.

Discussion Status

The discussion is active, with participants providing hints and encouraging the original poster to explore the problem further. There is a focus on understanding the mechanics involved rather than providing direct answers.

Contextual Notes

Participants note the importance of considering the center of mass and the direction of wheel rotation in relation to the forces acting on the car. There is an acknowledgment of the need for clearer descriptions and diagrams to facilitate understanding.

wai1997401
Messages
5
Reaction score
0

Homework Statement


When the car is at rest, normal reaction 1 and 2 act on the car's front wheel and rear wheel respectively . The problem is when the car starts to accelerates by rotating the wheels ,how would the normal reaction force change?

Homework Equations





The Attempt at a Solution


I don't understand why the normal reaction force action on the rear wheel will increase after accelerating. I am much obliged if one can help me :)
 
Physics news on Phys.org
Hello wai, and welcome to PF. Please help us helping you with working out number 2 and 3 a little more. That way you get more appropriate help, and it avoids you just getting an answer without really being helped or learning anything.

In the case of the car you want to draw a free body diagram of an accelerating car. It doesn't leave the ground and it stays level, so there are several balances to be drawn up.

Perhaps one hint: "normal reaction force action on the rear wheel will increase after accelerating" is wrong. That should be "during".

Perhaps another one: ever heard of a "wheelie" ? Might have something to do with accelerating !

Do you really need more hints ?
 
sorry for the poor description haha.i know that the change in normal reaction has something to do with friction, and the moment produced by friction about the center of gravity, but i really can't get why the R2 will increase.
 
There are at least 2 ways to look at it...

Hints:

1) At what height does friction with the road act?
At what height is the centre of mass?
Draw a diagram.

2) Which way do the wheels turn? Think about torque.
 
i have one question to ask : if the car moves to the right,the wheels rotate clockwisely, so the friction action the wheels is on the right?
 

Similar threads

Replies
11
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
7
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 24 ·
Replies
24
Views
2K
  • · Replies 7 ·
Replies
7
Views
5K
  • · Replies 17 ·
Replies
17
Views
4K
  • · Replies 13 ·
Replies
13
Views
4K