51. Tres trabajadores levantan un piano de 3.50 kN con rapidez constante hasta un departamento a 25.0 m arriba de la calle utilizando un sistema de polea sujeto al techo del edificio. Cada trabajador puede suminis- trar 165 W de potencia y el sistema de polea es 75% efi- ciente (de manera que 25% de la energía mecánica se pierde debido a la fricción en la polea). Ignorando la masa de la polea, encuentre el tiempo requerido para subir el piano desde la calle al departamento.​

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction 

It would stay the same