In 1801, the Italian astronomer Giusseppe Piazzi discovered a large, rocky body orbiting the Sun. The body was surrounded by other similar rocky bodies that traveled in the same orbit. What did Piazzi most likely discover? A. a moon B. an asteroid C. a comet D. a planet

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.

Abird flies directly overhead from where you stand at an altitude of 300.0 m and at a speed horizontal to the ground of 20.0 m/s. the bird has a mass of 2.0 kg. the radius vector to the bird makes an angle \thetaθ with respect to the ground. the radius vector to the bird and its momentum vector lie in the xyxy-plane. what is the bird’s angular momentum about the point where you are standing?

What is reflection, what is refraction, and what is diffraction. what some similarities or differences between the three.