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Before I write an email to my friend's tard physics professor, please let me know that I actually did this right.
Question: A car (m = 1250kg) travelling south at 1.30m/s and a truck (m = 4460kg) travelling west at 9.35m/s collide perfectly inelastically. Calculate the x and y components of the final velocity.
This should be simple, use conservation of momentum to find the final velocity via: [math]m_car * v_car + m_truck * v_truck = (m_car + m_truck) * v_final[/math] (assuming the car and truck are stuck together. You get v_final = ~7.59m/s. Then you find the angle in order to calculate the x and y components. The angle is found by putting the car's momentum on the x-axis of a triangle, and the truck's momentum on the y-axis, then use using the tangent formula to find that theta = 2.23 degrees. Then you take that angle and plug it into another triangle, where the final velocity is the hypotenuse. Solve for the x and y components using sin and cos formulas and you should find that the final answer is (-7.58, -0.295) and is using exact numbers every step along the way only rounding down to three sig figs at the very end.
Obviously the professor could have rounded more sloppily than I, but this dumb cunt's final answer is (-7.30, -0.295). That cannot be correct and even though I know this confidently, my friend doesn't trust me so if you could just confirm that the professor made a mistake (or is a dumb cunt) so I can show my friend, that would be very appreciated.
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You dumb nigger, if the collision is perfectly inelastic then all kinetic energy is converted to heat. You're even more retarded than the professor.
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>>8724298
It means the two objects stick together, retard.
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>>8724281
>dumb frogposter
>makes retarded mistakes and blames prof
Fucking use the law of momentum conservation for X and Y axis separately instead of going into trig to solve an easy as fuck problem.
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>>8724314
That's what I did, asshole, there's no other (simpler) way to solve the problem without finding the angle of using trig.
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you don't have any friends lol
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>>8724314
>>8724330
this was my initial response too but I got slightly different answers the two different ways.
handling x and y components separately, prof is right about x and both are wrong about y. handling them together and using trig, you're right (I think).
so now I'm worried that I'm fucking up the setup somehow.
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>>8724330
No, you're retarded. The simplest answer contains only basic operations without trigonometry.
Protip: Length of vector (A + B) doesn't equal length of A + length of B
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>>8724347
But then that means that magnitude of the velocity is 7.31 and if you use the conversation of momentum like I did, (m_car * v_car + m_truck * v_truck = (m_car + m_truck)*v_final, you get that v_final is 7.59. It is an inelastic collision so the two are supposed to stick together as one object.
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Y'all niggers have way too much free time to be learning these maths
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>>8724408
You're fucking adding vectors like if those were numbers. Are you even in college?
http://kcvs.ca/map/java/applets/collisions_2D/applethelp/lesson/lesson_2.html
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>>8724281
>Yfw "your friend's" physics professor lurks /sci/
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