Work-Energy Theorem Lab

Q: A 5 kg block is pushed with 20 N across a frictionless surface for 3 meters. What is its final speed if it starts from rest?

4.9 m/s W = Fd = (20)(3) = 60 J. W = \Delta K = \frac{1}{2}mv^2 - 0, so 60 = \frac{1}{2}(5)v^2 \Rightarrow v^2 = 24 \Rightarrow v \approx 4.9 m/s.

Push a block with adjustable force, mass, friction, and angle to verify W_net = ΔKE. Track kinetic energy, work by each force, and total net work with real-time graphs.

WHAT IS THE WORK-ENERGY THEOREM?

The Work-Energy Theorem states that the net work done on an object equals its change in kinetic energy: . This powerful principle connects forces (which do work) to motion (kinetic energy). In AP Physics 1, you must identify all forces acting on an object, calculate the work done by each, and sum them to find the net work.

HOW TO USE THIS VISUALIZATION

1. **Set Initial Conditions**: Adjust the applied force, mass, friction coefficient, and angle. 2. **Push the Block**: Watch the block accelerate and observe the real-time energy bar chart. 3. **Compare Work Values**: Notice how .

CORE FORMULAS

Work-Energy Theorem

Work by a constant force

Kinetic energy

AP EXAM CONNECTION

Unit: Unit 3: Work, Energy, and Power (Topic 3.1)
Learning Objective: 3.1.1

COMMON MISCONCEPTIONS

Forgetting to account for the angle when calculating work.
Thinking friction always does negative work (it does negative work on the sliding object, but positive work on what it's sliding against).
Confusing work with energy (work is energy transfer).

KEY TAKEAWAYS

The net work done on an object equals its change in kinetic energy.
Work is positive when the force and displacement are in the same direction.
Work is zero if the force is perpendicular to the displacement.
The theorem provides a scalar alternative to Newton's Second Law for solving motion problems.