Which one of the following forces cannot be expressed in terms of potential energy? Gravitational force Restoring force Frictional force Coulomb's force
❓ Question Which one of the following forces cannot be expressed in terms of potential energy ? Gravitational force Restoring force Frictional force Coulomb's force 🖼️ Question Image ✍️ Short Solution To solve this, we must identify which forces are conservative . 🔹 Step 1: Recall definitions A conservative force is one where the work done depends only on the initial and final positions , not on the path taken. For a conservative force , we can define a potential energy (U) such that F ⃗ = − ∇ U A non-conservative force depends on the path , so potential energy cannot be defined for it. 🔹 Step 2: Check each force Gravitational force ( F = m g F = mg ) Conservative: work depends only on vertical displacement. Potential energy: U = m g h U = m g h ✅ Restoring force (Hooke’s law: F = − k x F = -kx ) Conservative: work depends only on displacement from equilibrium. Potential energy: U = 1 2 k x 2 U = \frac{1}{2} k...