Consider a plastic rod that is being charged up by rubbing a wool cloth. It is then brought to an initially neutral metallic sphere, and allowed to touch the sphere for a few seconds. The rod is then separated from the sphere by a small distance. After becoming separated, the rod:. A) is repelled by the sphere. B) is attracted to the sphere. C) feels no force due to the sphere.

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?