A15.0-kg block is dragged over a rough, horizontal surface by a 75-n force acting at 21° above the horizontal. the block is displaced 5.7 m, and the coefficient of kinetic friction is 0.200. (a) find the work done on the block by the 75-n force.

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants

Which sections of the heating curve illustrate this process?

To fully describe the photoelectric effect, scientists must consider which of the following to be quantized? o a. both light and matter o b. matter only o c. light only o d. neither light nor matter