Una maquina lleva un paquete de 14 kg desde una posicion inicial de di = (1.5i + 1.75j + 1.2k) m en t = 0 a una posicion final df = (8.5i + 13j + 8.2k) m en t = 12 s. La fuerza constante que la maquina ejerce sobre el paquete es F = (2i + 4j + 6k) N. Para ese desplazamiento, encuentre (a) el trabajo que realiza la fuerza de la maquina sobre el paquete y (b) la potencia promedio de la fuerza de la maquina sobre el paquete

The metal wire in an incandescent lightbulb glows when the light is switched on and stops glowing when it is switched off. this simple process iswhich kind of a change? a.a physical changeb. a chemical changec. a nuclear changed. an ionic change

Aplayground slide is 8.80 ft long and makes an angle of 25.0° with the horizontal. a 63.0-kg child, initially at the top, slides all the way down to the bottom of the slide. (a) choosing the bottom of the slide as the reference configuration, what is the system's potential energy when the child is at the top and at the bottom of the slide? what is the change in potential energy as the child slides from the top to the bottom of the slide? (include the sign of the value in your answer.)

An astronaut on the moon throws a baseball upward. the astronaut is 6 ft, 6 in. tall, and the initial velocity of the ball is 3030 ft per sec. the height s of the ball in feet is given by the equation s equals negative 2.7 t squared plus 30 t plus 6.5s=−2.7t2+30t+6.5, where t is the number of seconds after the ball was thrown. complete parts a and b.