Which of the following statements best describes the characteristic of the restoring force in the spring-mass system described in the introduction? the restoring force is constant. the restoring force is directly proportional to the displacement of the block. the restoring force is proportional to the mass of the block. the restoring force is maximum when the block is in the equilibrium position.

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?