A spinning disk is rotating at a rate of 5 rad/s in the positive counterclock-wise direction. If the disk is subjected to an angular acceleration in the counterclock-wise direction at a rate of 2 rad/s2, Find the wheel's angular velocity in rad/s after 4 s.

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?