Anna begins jogging at a steady 3 m/sec down the middle of lane one of a straight track. Elsa starts even with her in the center of lane two but moves at 5 m/sec. At the instant they begin, Olaf is located 45 meters down the track in lane four, and is heading towards them in his lane at 6 m/sec. After how many seconds will the runners lie in a straight line?

Larry bar opened a frame shop and completed these transactions: larry started the shop by investing $41,100 cash and equipment valued at $19,100 in exchange for common stock. purchased $180 of office supplies on credit. paid $2,300 cash for the receptionist's salary. sold a custom frame service and collected $5,600 cash on the sale. completed framing services and billed the client $310. what was the balance of the cash account after these transactions were posted?

Tree diagram to find the prime factors of 18

Asmall (but heavy) particle placed in a glass of water will follow a zigzag motion because the particle will bounce off of the water molecules it meets. this is called brownian motion. a physicist simulates this on a computer, by varying the distance a particle can travel (called the mean free length), on average, before it collides with a water molecule and assigning the change in motion to be one of 8 directions, each with a similar probability. by running the simulated particle (with the same mean free length) many times she determines that it should take 15 seconds, on average, for the particle to fall to the bottom, with a standard deviation of 1.5 seconds. next she lets a real particle fall through a glass of water and finds that it took 18 seconds. what does she conclude, and why?