A10-meter-long spear is thrown at a relativistic speed through a 10-meter-long pipe (both measured when at rest.) when the spear passes through the pipe,
a. the pipe shrinks so the spear extends at both ends.
b. both shrink equally so the pipe barely covers the spear.
c. the spear shrinks so the pipe completely covers it.
d. any of the above, depending on the motion of the observer
e. none of the above

Imagine that you have two balloons (or, better yet, actually inflate two balloons, if possible). create static electricity around one of the balloons by rubbing it against your hair or your sweater and then bring that balloon close to the other balloon, which has not been charged. try this with at least one other object—and for variety in the discussion, avoid using an object already described by your classmates. then, for your initial post to the discussion, answer the following questions: what happened with the two balloons?