A man stands on a platform that is rotating (without friction) with an angular speed of 1.2 rev/s; his arms are outstretched and he holds a brick in each had. The rotational inertia of the system consisting of the man, bricks, and platform about the central vertical axis of the platform is 6.0 kgm2. If by moving the bricks the man decreases the rotational inertia of the system to 2.0 kgm2, what are (a) the resulting angular speed of the platform and (b) the ratio of the new kinetic energy of the system to the original kinetic energy?

From 0 to 5 seconds john pushed a box 5 meters. from 5 to 10 seconds, paul pushed the same box another 5 meters. who did more work? a. john b. paul c. john and paul did the same amount of work.

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.

Do you think you could give me the answers to #29?