Un ascensor de masa 495 kg sube a lo largo de 4 pisos (cada piso tiene una altura de 1,2 m) con una aceleración de 0,73 m/s2. Sabiendo que la fuerza de roce en el ascensor al subir es 1350 N. Calcular el trabajo total y la potencia realizada sobre el ascensor para subir los cuatro pisos, si tarda 24 s.

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.