2.A driver of mass 50kg at the end of cantilever diving board of 1m length. The diver oscillates at a frequency of 2 Hz. What is the flexural rigidity EI of the diving board?

Damping due to Friction

Friction is a force that opposes the relative motion or tendency of motion between two surfaces in contact. When two surfaces are in contact and one is in motion with respect to the other, friction arises due to the interaction between the microscopic irregularities on the surfaces. This frictional force not only resists the motion but also dissipates energy in the form of heat. The damping that results from this frictional force is referred to as frictional damping.

Explanation

Frictional damping can occur in various scenarios, such as in mechanical systems, civil structures, and vehicles. Here's an explanation of how frictional damping works:

1. Frictional Forces: When two surfaces are in contact and one is moving relative to the other, the frictional force opposes the motion. This force is proportional to the normal force between the surfaces and can be expressed as F_friction = μ * N, where μ is the coefficient of friction and N is the normal force.

2. Energy Dissipation: As the frictional force opposes the motion, it causes energy to be dissipated in the form of heat. This energy is converted from the kinetic energy of the moving object, leading to a gradual decrease in the motion and eventually coming to rest.

3. Damping Effect: The dissipation of energy through friction leads to a damping effect, which reduces the amplitude of vibrations or oscillations. Frictional damping can be particularly important in situations where it is desirable to dampen oscillations and vibrations, such as in damping systems for buildings or vehicles.

4. Dependence on Surface Characteristics: The magnitude of frictional damping depends on the surface characteristics and the coefficient of friction between the two surfaces. Rough surfaces with high coefficients of friction tend to exhibit higher levels of frictional damping.

5. Applications: Frictional damping is widely used in various engineering applications. For example, in civil engineering, frictional damping is utilized in the design of seismic dampers to absorb and dissipate energy during earthquakes. In mechanical systems, frictional damping is employed in devices such as shock absorbers to reduce vibrations and oscillations.

In conclusion, the damping that results from the friction between two surfaces is referred to as frictional damping. This damping arises from the opposing force generated by the interaction between the surfaces and leads to the dissipation of energy in the form of heat. Frictional damping plays a crucial role in reducing vibrations and oscillations in various engineering applications.