A hollow conducting sphere has an internal radius of r1 = 1. 9 cm and an external radius of r2 = 3. 1 cm. The sphere has a net charge of Q = 1. 9 nC. a) What is the magnitude of the electric field in the cavity at the center of the sphere, in newtons per coulomb?

b) What is the magnitude of the field, in newtons per coulomb, inside the conductor, when r1 < r < r2?

c) What is the magnitude of the field, in newtons per coulomb, at a distance r = 5. 9 m away from the center of the sphere?

How have the competing explanations' experiments on atoms affected the development of the atomic model?

Afisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. it takes a time of 2.20 s for the boat to travel from its highest point to its lowest, a total distance of 0.670 m . the fisherman sees that the wave crests are spaced a horizontal distance of 5.80 m apart. (a) how much is the wavelength? (b) find the period of the wave. (c) how fast are the waves traveling? (d) what is the amplitude a of each wave?

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i.e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i.e. include the distance traveled to the first encounter)