In a closed system with no friction, a red sphere of 2.5 kg stands stationary. A blue sphere with a mass of 5.8 kg approaches the first sphere with a speed of 4.1 m/s. The two collide. After the collision, the blue sphere begins moving forward with a speed of 1.3 m/s. What is the velocity
of the red sphere after the collision? (Show all work)

Research and discuss the aurora borealis in terms of electric charges, magnetic fields, and forces. which times of the year are best for seeing the northern lights, and where are the best places to view them? explain your answers. also identify links to good images. if you’ve ever seen the aurora borealis, describe your experience and note the time and place that you saw it.