A deuteron of mass M is moving at speed v before colliding with an immobile α-particle of mass 2M. The deuteron is deviated 90° from its initial direction. Knowing that the collision is elastic, determine the angle of the trajectory of the α-particle with respect to the deuteron’s initial path.

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?