"Edward Smith" wrote in message
...
I'm not above a few hints:
5. Superman jumps in front of a speeding bus, puts out his arms and
stops the bus in 1 second. If the bus was traveling at 37 mph and
weighs 57000 Lb. What force did Superman apply to the bus?
Hints:
Use the "Impulse Equation" to relate the average force to the change
in momentum in a period of time.
For the mass of the bus you use W = m · g which gives m = W / g .
Superman applied a force of__________ Lb. (Note English units.)
You know, in England - physicists use sensible units these days.
Use F=ma. You can figure out the acceleration. Two things to be
careful of. Watch the gravity term and make sure your units are
consistant.
The bus is going at about 16 m/s and the bus is about 20,000 kg.
a is 16 m/s in a second. So, thats 320,000N
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