Un helicóptero de abastecimiento militar suelta un paquete con provisiones desde una altura de 420 metros ,determina en cuanto tiempo llega al suelo

Ameter stick is pivoted at the 0.50-m line. a 3.0-kg object is hung from the 0.15-m line. where should a 5.0-kg object be hung to achieve equilibrium (the meter stick oriented horizontal and motionless)?

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

Amagnetic field applies forces on: a)static chargesb)moving chargesc)water flow