What is the density of a rock with a mass of .235kg

Alexander calder's mobiles are an example of motion because it uses forces of wind and water.

Aperson standing in a canoe exerts a force of 700 n to throw an anchor over the side. find the acceleration of the canoe if the total mass of the canoe and the person is 100 kg?

What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th