3.
Ans: 3 m/s in opposite direction)
If a fly collides with the windshield of a fast-moving bus, (AS))
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(a) Is the impact force experienced, same for the fly and the bus? Why?
(b) Is the same acceleration experienced by the fly and the bus? Why?
Answers
Answer:
ok sir you bro and the question is what you want
Answer:
I'm assuming you mean when the fly collides with the bus.
the impact force is defined as the force exerted onto an object to cause an impact - a change in momentum - on it. So technically, in the case of a collision, the fly and the bus would have exerted and experienced identical impact force. Because by newton’s third law, every action has an equal and opposite reaction. Or as my physics teacher likes us to (more accurately) put it:
“if object A exerts a force on object B, object B exerts the same force back onto object A”
seems a little counterintuitive when applied to the situation of the bus and the fly, since you can imagine the amount of damage a fly would sustain from ramming into a bus, whereas any bus most probably would not be hindered by any single fly crash into it, no matter the speed.
The key here lies in momentum. as mentioned before, an impact force is defined as the force to cause a change in momentum. in fact, the equation states that
Force x time of impact = momentum after - momentum before
seeing as the two collides with each other, the time of impact would be the same for both, as is the impact force, as we have just shown above. Hence, it is safe to assume the change in momentum in the bus and the fly is identical.
however, momentum is defined as such:
momentum of an object = mass of an object x velocity of an object
rearranging gives:
velocity of an object = momentum of an object/mass of an object
as you can see, with the same momentum change the velocity of the bus is going to change very little compared with the velocity change in the fly, simply because of how much more massive it is, and dividing by a much larger number on the right hand side would give a much smaller number of the left.
Hence, during collision, the fly and the bus exerts the same impact force onto each other, however the acceleration (change in velocity) of the fly will be much, much greater than that of the bus
Explanation: