Today, we reviewed momentum and impulse more. The picture to the left is one of the examples that were demonstrated in class. Someone would be sitting on the hover board while another would be sitting on the danger board. They threw a medicine ball between them, and when they did, both the person throwing the ball and the person catching the ball moved backwards. The reason thrower's moving back was because as they exerted force onto the ball, the ball was exerting the same amount of force onto them, which caused them to accelerate backwards. As for the catcher, when catching the ball its momentum was transferred to the catcher, since momentum is conserved. In the situations, one person moved farther back than the other (normally it was the person on the hover board, but that could've been because the danger board had friction) and this is because they had less mass than the other, so they had a higher velocity.
The only new thing I remember learning today is the rule that under the curve of a Force vs. Time graph, the area is equal to impulse. Speaking of impulse, we went over it a lot today and I still find it incredibly confusing, so I thought I would just write out the equations/definitions as a review for myself and whoever else wants it.
Impulse: the average force exerted upon an object multiplied by the time the force is acting on the object. Change in momentum of an object.
Impulse = J or I ('cause it's just cool like that)
J = change in momentum = mv - mv
o = avg. force • change in time
That was a really good picture and explanation of the hover/danger board throw-y whatever activity we did yesterday. I didn't totally understand it when it was happening, but your clarification helped a lot, as did your review of equations at the end.
ReplyDeleteYOUR BACKROUND <3 <3 And your post helped to clear up some scary momentum things that I don't want to be tested on D:
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