A6.0-cm-diameter disk emits light uniformly from its surface. 20 cm from this disk, along its axis, is an 7.0-cm-diameter opaque black disk; the faces of the two disks are parallel. 20 cm beyond the black disk is a white viewing screen. the lighted disk illuminates the screen, but there’s a shadow in the center due to the black disk. what is the diameter of the completely dark part of this shadow?

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?

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a.true or b.false

When using the scientist method, which step comes last?