A145 g baseball is dropped from a tree 13.0 m above the ground. (a) with what speed would it hit the ground if air resistance was negligible? (b) if it actually hits the ground with a speed of 8.00 m/s, what is the average force of air resistance exerted on it?

The speed of light can be used to measure the

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/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