Work done (By non -conservative force – Friction)

Work Done by a Non-Conservative Force Experiment – For Schools, Teachers, and Students

Definition

Work done by a non-conservative force refers to the work performed by forces that depend on the path taken by an object and do not have an associated potential energy. These forces dissipate mechanical energy into other forms, such as heat or sound.

Examples of non-conservative forces include:

• Friction
• Air Resistance
• Applied Forces

This concept is demonstrated in Dencity – Physics app and Simulations to enhance interactive learning.

Theory

Non-conservative forces do not conserve mechanical energy. The work done by non-conservative forces can be calculated using:

W_nc = ∫ F_nc · dr

Unlike conservative forces, the work done by non-conservative forces is path-dependent, and the energy dissipated due to these forces cannot be fully recovered.

Work-Energy Relationship with Non-Conservative Forces

For a system involving non-conservative forces, the total work-energy equation is:

W_nc = ΔK + ΔU

where:

• W_nc = Work done by non-conservative forces
• ΔK = Change in kinetic energy
• ΔU = Change in potential energy

For forces like friction or air resistance, the work done is typically negative because these forces oppose motion, dissipating energy.

Examples of Work Done by Non-Conservative Forces

1. Frictional Force:
   • The work done by friction for an object moving distance (s) is:
     W_f = -F_f s = -μ F_n s
     where:
     • F_f = Frictional force
     • μ = Coefficient of friction
     • F_n = Normal force
2. Air Resistance:
   • The work done by air resistance depends on the drag force, which is proportional to the velocity of the object:
     F_air = -(1/2) C_d ρ A v²
     where:
     • C_d = Drag coefficient
     • ρ = Air density
     • A = Cross-sectional area of the object

Real-World Applications

The concept of work done by non-conservative forces is applied in:

• Modeling energy dissipation in mechanical systems.
• Understanding energy loss in vehicles due to friction and air resistance.
• Calculating energy requirements in industrial applications where frictional forces play a role.
• Online Science Lab: Allows students to simulate energy loss due to non-conservative forces.

Observations and Key Learnings

• Work done by non-conservative forces depends on the path taken.
• Friction and air resistance always dissipate energy, making their contribution negative in the work-energy equation.
• The greater the distance traveled, the higher the energy loss due to non-conservative forces.
• Non-conservative forces reduce the total mechanical energy of a system.

The Work Done by a Non-Conservative Force Experiment helps students understand how forces like friction, air resistance, and applied forces affect motion by dissipating mechanical energy into heat, sound, or other forms. Unlike conservative forces, non-conservative forces depend on the path taken and reduce the total mechanical energy of a system.

Using online science experiments, students can explore how friction and air resistance impact real-world motion. Our science education app and online physics lab provide interactive simulations that help visualize energy loss due to non-conservative forces.

With online tools for teachers, educators can enhance classroom learning by demonstrating energy dissipation in mechanical systems, vehicle motion, and industrial processes. This experiment allows students to apply physics concepts in practical scenarios, making learning more engaging and effective.