A wheel will start rolling when a force is applied and there is a resistive force or friction at the point of contact with the ground. The force may be a torque or a linear push on the wheel. Static friction causes the rolling motion. It is also called the traction of the wheel.

No longer rolling down the hill. Teleport the ball back to your hand….

1. nuke it a few times.
2. level the hill.
3. make the ball out of neutronium.
4. make it so dense it becomes a black hole.
5. Put it in an arc furnace.
6. dont put the ball on the hill.
7. superglue the ball in place.
8. make your fruends hold it.

Rolling without slipping commonly occurs when an object such as a wheel, cylinder, or ball rolls on a surface without any skidding. The wheel rolls without slipping only if there is no horizontal movement of the wheel at the contact point P (with respect to the surface/ground).

Combination of rotational and translational motion: • Center of mass moves in a translational motion. The rest of the body is rotating around the center of mass. II. Pure Rotational Motion: Page 2 2 • The whole object is revolving around a point on the object in contact with the surface.

We seem to have discovered the forces that can slow a rolling body’s motion. But if the body slows, it loses kinetic energy of rotation, loses forward momentum, and loses angular momentum.

Rolling motion is equivalent to pure rotation about the axis at the point of contact, which is parallel to central axis. Rolling motion as pure rotation Each particle of the body can be considered to rotate about the axis through the contact point with same angular velocity.

Rotational motion means that your body moves around a fixed axis, for exapmle consider the rotation of the Earth. Rolling is a special kind of motion, when a body is rotating around a moving axis. The axis is translating, while the body is rotating around it.

We can also look at rolling motion as a consequence of the torque on an object as it moves down a slope. Therefore, we can look at the torque exerted around this point of contact by the force of gravity. …

The torque is obtained by integrating the frictional force multiplied by roll radius over the arc of contact (lagging and leading zones). The negative sign before the second term is due to the fact that in leading zone the metal moves faster than the rolls hence it helps to rotate the rolls.

Rolling and Newton’s first law Similarly, according to Newton’s first law for rotation, if net external torque is zero, then rotation of the object i.e. angular velocity remains same. It means, then, that a body in uniform rolling motion shall roll with the same velocity.

While tangential contact components of force (due to friction) always act in a direction to oppose slipping or sliding at the surfaces, the force components normal to the surface always act to oppose the acceleration of the rolling body.

In rolling motion without slipping, a static friction force is present between the rolling object and the surface. A rigid rotating body has angular momentum directed along the axis of rotation. 11.4: Conservation of Angular Momentum. In the absence of external torques, a system’s total angular momentum is conserved.

If an object is rolling without slipping, then its kinetic energy can be expressed as the sum of the translational kinetic energy of its center of mass plus the rotational kinetic energy about the center of mass.