Work Done By External Force Formula

Work-Energy Formula:

\[ W_{ext} = \Delta U + \Delta KE \]

Work Done by External Force (W_ext):

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1. What is the Work Done by External Force Formula?

Definition: This formula calculates the work done by external forces on a system, accounting for changes in both potential and kinetic energy.

Purpose: It's fundamental in physics for analyzing energy transformations in mechanical systems with external influences.

2. How Does the Formula Work?

The formula is expressed as:

\[ W_{ext} = \Delta U + \Delta KE \]

Where:

\( W_{ext} \) — Work done by external forces (Joules)
\( \Delta U \) — Change in potential energy (Joules)
\( \Delta KE \) — Change in kinetic energy (Joules)

Explanation: The total work done by external forces equals the sum of the system's change in potential energy and change in kinetic energy.

3. Importance of the Formula

Details: This principle is crucial for understanding energy conservation in non-isolated systems and analyzing real-world physics problems involving work and energy.

4. Using the Calculator

Tips: Enter both the change in potential energy and change in kinetic energy in joules. The calculator will sum them to find the work done by external forces.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between W_ext and total work?
A: W_ext specifically accounts for work done by forces external to the system, excluding internal forces.

Q2: Can ΔU or ΔKE be negative?
A: Yes, both can be negative if potential or kinetic energy decreases, which affects the work calculation.

Q3: What if there's no change in potential energy?
A: If ΔU = 0, then W_ext = ΔKE (all external work goes to changing kinetic energy).

Q4: How is this related to the work-energy theorem?
A: This is an extension that includes potential energy changes, not just kinetic energy.

Q5: What units should I use?
A: All quantities must be in consistent units (Joules in this calculator).