Work done formula.

**The reasoning** Work is done when a force **moves** an object through a distance. The formula is: **Work = Force × Distance** (W = F × d) Think of pushing a heavy box across the floor. You apply force, and the box moves a certain distance. The work you do depends on both how hard you push (force) and how far the box travels (distance). If the box doesn't move at all, no work is done — even if you're sweating! The unit is Joules (J), which equals Newton × meter (N·m). **Why the wrong options tempt you** - **A (Force × velocity)** confuses work with **momentum** or **power**. Velocity is speed, not distance covered. - **C (Mass × velocity)** is actually the formula for **momentum** (p = mv), not work. Easy mix-up! - **D (Power × time)** is sneaky because it *can* give you work (since Power = Work/Time), but it's not the **direct definition** of work itself. **Quick takeaway** Work needs two things: a force that **acts** and a distance the object **actually moves** — no movement, no work, no matter how hard you try!