Hi I need help on the following :(

6. The 1992 world speed record for a bicycle (human-powered vehicle) was set by Chris Huber. His time through the measured 200m stretch was a sizzling 6,509s, at which he commented, "Cogito crgo zoom!" (I think, therefore I go fast!). In 2001, Sam Whittingham beat Huber's record by 19.0 km/h. What was Whittingham's time through the 200 m?

7. Two trains, each having a speed of 30 km/h, are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 60 km apart and heads directly for the other train. On reaching the other train, the (crazy) bird flies directly back to the first train, and so forth. What is the total distance the bird travels before the trains collide?

8. Panic escape. Figure 2-24 shows a general situation in which a stream of people attempt to escape through an exit door that turns out be locked. The people move toward the door at speed v, = 3.50 m/s. are each d=0.25 m in depth, and are separated by L=1.75 m. The arrangement in Fig. 2-24 occurs at time t=0.

a) At what average rate does the layer of people at the door increase?

b) At what time does the layer's depth reach 5.0m? (The answers reveal how quickly such a situation becomes dangerous.)

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