Author Topic: Collisions question? (Read 358 times) Tweet Share

onur369 · « **on:** April 22, 2011, 05:49:42 pm »

Hey guys, I am doing a trial exam and I got stuck on question 11 (see below), I am constantly getting 2.7ms but Im not sure if its correct, can somebody please clear things up for me?

xZero · « **Reply #1 on:** April 22, 2011, 06:05:32 pm »

the initial momentum is 5 x 80 = 400 kgms^-1

the final momentum is also 400, if Ben moves off at 8 ms^-1, then his momentum is 8 x 65 = 520 kgms^-1. The final momentum can also be calculated by combining Ben's and Charles' momentum, so 520 + P = 400, p = -120, mv = -120, v = -1.5 ms^-1 or v = 1.5ms^-1 to the right

onur369 · « **Reply #2 on:** April 22, 2011, 06:07:22 pm »

Thanks mate

Vincezor · « **Reply #3 on:** April 22, 2011, 07:10:03 pm »

Question 11

$P(Initial) = {80*5}$
$= 400kgms^{-1}$

According the the law of conservation of momentum,

$P(Initial) = P(Final)$

Taking Left as positive:

$400 = P(Charles) + P(Ben)$
$400 = P(Charles) + 65*8$
$-120 = P(Charles)$
$-120 = 80 * v$
$v(Charles) = 1.5ms^{-1}$ RIGHT

Sorry I know the answer was posted above, just wanted to try out the LaTeX

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Author Topic: Collisions question? (Read 358 times) Tweet Share

onur369

Collisions question?

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onur369

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Vincezor

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