Let's try an example that applies elastic potential energy and conservation of energy. A block with mass of 3.00 kg is attached to a horizontal spring with spring constant 600 N/m. The block is pulled 0.0500 m beyond its equilibrium position. Assume the surface the block rests on is frictionless. www m 0 X; X What is the speed (in meters per second) of the block at the position x = 0.0250 m? 3.16 Incorrect. Use conservation of energy to solve for the speed. Remember, there are no nonconservative forces in this case. The system will have both elastic potential and kinetic energy at this position. m/s What is the speed (in meters per second) of the block when it reaches its equilibrium point? 0.707 Correct. The initial elastic potential energy is completely converted to kinetic energy when the block returns to its equilibrium position. Remember, there is no friction force. m/s