Calcular gráfica y analíticamente la resultante del sistema de fuerzas. ¿Qué condiciones debe reunir una fuerza F4 para que haya equilibrio? Datos: F1 = 20 N; F2 = 15 N y F3 = 7 N.

What is the function of the commutator in a dc motor? a. to spin the magnet b. to change direct current into alternating current c. to change alternating current into direct current d. to spin the wire coil

What must be the same for any two resistors that are connected in series ? a. the potntial diffrence across each b. the rate at which charge moves through each c. the rate at which energy is used by each d. the resistance to the flow of charge of each

Very large accelerations can injure the body, especially if they last for a considerable length of time. one model used to gauge the likelihood of injury is the severity index ( ), defined as =/ . in the expression, is the duration of the accleration, but is not equal to the acceleration. rather, is a dimensionless constant that = the number of multiples of that the acceleration is equal to. in one set of studies of rear-end collisions, a person's velocity increases by 13.7 km/h with an acceleration of 36.0 m/s2 . let the + direction point in the direction the car is traveling. what is the severity index for the collision?