Why Is Friction Opposite to Wheel Acceleration in Rolling Motion?

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SUMMARY

The discussion centers on the mechanics of rolling motion, specifically addressing the frictional force acting on a wheel subjected to a constant horizontal force of 10 N. The wheel, with a mass of 10 kg and a radius of 0.4 m, experiences an acceleration of 0.6 m/s². The calculated frictional force is -4 N, indicating that friction opposes the direction of acceleration. This phenomenon is explained by Newton's third law, which clarifies that friction acts in the opposite direction to prevent slipping, despite the wheel's tendency to accelerate forward.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Basic principles of rotational dynamics
  • Familiarity with frictional forces in mechanics
  • Knowledge of kinematic equations
NEXT STEPS
  • Study the role of static and kinetic friction in rolling motion
  • Learn about torque and its effects on wheel acceleration
  • Explore the implications of Newton's third law in various mechanical systems
  • Investigate the relationship between force, mass, and acceleration in different contexts
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators seeking to clarify concepts related to rolling motion and frictional forces.

1MileCrash
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Homework Statement



In the figure, a constant horizontal force Fa magnitude 10 is applied to a wheel of mass 10 kg and radius .4 m. The wheel rolls smoothly on the horizontal surface, and the acceleration of the center of mass has magnitude .6 m/s^2.

Find frictional force on wheel.


Homework Equations





The Attempt at a Solution



f = ma

10 + friction = ma = 6

friction = -4

I don't understand why my friction direction is opposite of the direction the wheel is accelerating. It should be in the same direction. Obviously the math is fine, but why is the friction going in the same direction that the wheel has the tendency to slide in?
 
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Newton's third law of motion.
 
1MileCrash said:

Homework Statement



In the figure, a constant horizontal force Fa magnitude 10 is applied to a wheel of mass 10 kg and radius .4 m. The wheel rolls smoothly on the horizontal surface, and the acceleration of the center of mass has magnitude .6 m/s^2.

Find frictional force on wheel.


Homework Equations





The Attempt at a Solution



f = ma

10 + friction = ma = 6

friction = -4

I don't understand why my friction direction is opposite of the direction the wheel is accelerating. It should be in the same direction. Obviously the math is fine, but why is the friction going in the same direction that the wheel has the tendency to slide in?

Quite hard to see the difficulty as I can't find "the figure"
 

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