Es sabido que las llamadas "balas perdidas" son extremadamente peligrosas, al grado que se aconseja no salir al aire libre en ciertos momentos de fiestas nacionales. Considerando que la rapidez inicial promedio de una bala de bajo calibre es de aproximadamente 300 m/s calcula: a) la altura vertical máxima alcanzada y el tiempo de subida de la bala. b)Considerando que la bala comienza su descenso después de alcanzar su altura máxima ¿con qué rapidez llega al suelo?, c) ¿cuanto tiempo permanece en el aire?

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 740 n/m. it is initially at rest on an inclined plane that is at an angle of theta= 26 with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is uk = 0.17. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. the block's initial mechanical energy is 9.472 j. b. if the spring pushes the block up the incline, what distance l in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.