Which of the following employs the use of an external combustion engine?

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

Two carts, one of mass 2m and one of mass m, approach each other with the same speed, v. when the carts collide, they hook together. assume that positive momentum is to the right. which graph best represents the momentum of both carts over time, before and after the collision?

A10nc charge sits at a point in space where the magnitude of the electric field is 1500 n/c. what will the magnitude of the field be if the 10 nc charge is replaced by a 20 nc charge? assume the system is big enough to consider the charges as small test charges.