Conservation of Energy
Watch this video:
The hummer is a large vehicle with a lot of mass. Let's estimate that it's mass is 3000 kg and it was moving at 15 m/s. How much energy does it have?
EK = (1/2) mv^2 = 338 kJ
If all this energy went into a person of mass 52 kg how fast would the person fly out of the hummer?
Answer: 114 m/s <-- that's over 410 km/h!!
What keeps the person from flying out? Where does all the energy go when the hummer crashes? Energy is never destroyed, it can only be converted from one form to another. If we want to protect the human inside, we have to make sure the energy is spread out over the car rather than into the person. Watch this video to see how it's done:
Here are the notes along with the example questions:
Here are some solutions to yesterday's worksheet:
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