A pole−vaulter holds a 16 ft. pole. A barn has doors at both ends, 10 ft. apart. The pole−vaulter on the outside of the barn begins running toward one of the open barn doors, holding the pole level in the direction he’s running. When passing through the barn, the pole fits (barely) entirely within the barn all at once. (a) How fast is the pole−vaulter running? (b) According to whom−the pole−vaulter or an observer stationary in the barn−does the pole fit in all at once? (c) According to the other person, which occurs first, the front end of the pole leaving the barn or the back end entering, and (d) what is the time interval between these two events’?
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