ENEM 2013 - Questão 85 resolvida (Caderno Azul) - Física - Eletricidade - Prof. Marcelo Boaro

VISIT: http://www.canalfisica.net.br/doacoes/ Hey everyone! How are you? This is another solved exercise from the 2013 ENEM (National High School Exam) for you! Hugs, happy studying, and God bless you! HERE ARE THE LINKS:    • ENEM 2013 - Questão 48 resolvida (Caderno ...   A device is developed to automatically open a door in which a button, when pressed, causes an electric current i = 6 A to flow through a conducting rod of length L = 5 cm, whose midpoint is attached to a spring with spring constant k = 5 × 10–2 N/cm. The spring-conductor system is immersed in a uniform magnetic field perpendicular to the plane. When the button is pressed, the bar will leave the equilibrium position at an average speed of 5 m/s and will reach the turnstile in 6 milliseconds, opening the door.