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I had 2 HW questions that I didn't get for my physics class, and I would really appreciated if you could explain them to me. They're pretty simple, I think, but the way they're worded makes it difficult to picture.

1) Two trains, each having a speed of 30 km/hr, are headed at each other on the same straight track. A bird that can fly 60 k /hr 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 it flies directly back to the first train, and so forth. ( We have no idea why a bird would behave this way). What is the total distance the bird travels?

2) If a particle's position is given by x= 4mp - (12m/s)t+(3 m/s^2)(t^2), what is its velocity at t1 = 1 s?

For this problem, the correct answer is -6m/s (answers on the back of the book) but I don't know how to get that.

Thank you so much for your time!