Spring Forces Practice Test

A $0.50,\text{kg}$ block is attached to an ideal horizontal spring. The equilibrium position is defined as $x=0$ where the spring is neither stretched nor compressed. Rightward displacement is positive. The block is held at $x=+0.10,\text{m}$ (spring stretched) and released from rest. Which describes the spring force on the block at that instant?

A cart attached to an ideal spring moves on a frictionless track. Equilibrium is $x=0$ at the spring’s natural length, and +$x$ points right. When the cart is at $x=+0.04,\text{m}$, the spring force on it is $F_s=-2.0,\text{N}$. What is the spring force when the cart is at $x=+0.08,\text{m}$?