Summarize the evidence indicating that over several hundreds of years or more there have been variations in the level of the solar activity.

Two identical 82 mg dust particles very far apart (pee 0) are moving directly toward each other at a speed of 3698 m/s. the charge on each is-719 ? c. determine how close they will get to each other. let k = 9x109 n-m2/c2 & ignore gravity.

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 •  

Consider a one meter long horizontal pipe with a constant 100 cm^2 cross sectional area. water flows rightward into the pipe at x = 0 with flow velocity 02m/sec at every point within the pipe intake area. at x=1, the rightward flow rate is 0.192 m/sec. assume the water is a conserved quantity in the pipe, so there must be a leak (a sink) somewhere in the pipe. 1. compute net volumetric flow of the source if the system to be in equilibrium. 2. now assume the pipe in the problem has no leaks. compute the net volumetric rate of change for the system.