Un camion sin control con falla en sus frenos baja por una pendiente a 130 km/h, justo antes que el conductor dirija al vehıculo hacia arriba en una rampa de escape de emergencia, sin friccion y con una inclinacion de θ = 15o. La masa del camion es 1.2×104 kg. (a) ¿Que longitud L mınima debe tener la rampa si el camion debe detenerse (momentaneamente) a lo largo de ella?

When a charged balloon sticks to a wall, the downward gravitational force is balanced by an upward static friction force. the normal force is provided by the electrical attraction between the charged balloon and the equal but oppositely charged polarization induced in the wall's molecules. if the mass of a balloon is 1.2 g, its coefficient of static friction with the wall is 0.71, and the average distance between the opposite charges is 0.80 mm, what minimum amount of charge must be placed on the balloon in order for it to stick to the wall? express your answer to two significant figures and include appropriate units.