An isolated system allows which of the following to enter or exit a. neither energy nor matter b. energy but not matter c. matter and energy d. matter but not energy

Atransverse wave is traveling on a string stretched along the horizontal x-axis. the equation for the vertical displacement y of the string is given by y = (1.8 x 10-3)cos[π(13x - 60t)], where all quantities are in si units. what is the maximum speed of a particle of the string

Two identical small charged spheres are a certain distance apart, and each one initially experiences an electrostatic force of magnitude f due to the other. with time, charge gradually leaks off of both spheres. when each of the spheres has lost half its initial charge, the magnitude of the electrostatic force will be

What tightening torque should be used for a hexagonal head screw (not split-bolt) on a 250 kcmil conductor?