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2 years ago

Applying the Law of Conservation of Momentum

Physics

1 answer:

IgorC [24]2 years ago

6 0

answer

the final velocity is half of train car B's initial velocity

explanation

the conservation of momentum states that the initial and final total momentum are equal

m1v1 + m2v2 for initial momentum

(m1 + m2)v3 for final momentum because both cars stick together so their masses are combined

m1v1 + m2v2 = (m1 + m2)v3

since the mass of both are the same, m1 = m2

m1v1 + m1v2 = (m1 + m1)v3

m1(v1 + v2) = 2m1v3

divide both sides by m1

v1 + v2 = 2v3

since train car A is initially at rest, v1 = 0

v2 = 2v3

v3 = v2 * 1/2

the final velocity is half of train car B's initial velocity

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Explanation:

Since fluid is pumping in and out at the same rate (5L/min), the total fluid volume in the tank stays constant at 350L. Only the amount of salt and its concentration changed overtime.

Let A(t) be the amount of salt (g) at time t and C(t) (g/L) be the concentration at time t

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The well-mixed solution is pouring out at the rate of 5L/min at concentration C(t) so the salt outcome rate is 5C g/min

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$y = ce^{bt} + \frac{a}{b}$

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2 years ago

Starting from the front door of your ranch house, you walk 50.0 m due east to your windmill, and then you turn around and slowly

Hunter-Best [27]

Answer:

Average velocity

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Average speed,

$S=\frac{D}{t}\\ S=\frac{90}{70}\\ S=1.29\frac{m}{s}$

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We have to find the average velocity. We know that velocity is defined as the rate of change of displacement with respect to time.

To find the average velocity we have to find the total displacement.

since displacement along east direction is 50m

and displacement along west=40m

so total displacement,

$d=50m-40m\\d=10m$

total time,

$t=28 s+42 s\\t=70 s$

therefore, average velocity

$v=\frac{d}{t}\\ v=\frac{10m}{70s}\\v=.1428 \frac{m}{s}$

(b)Average Speed:

Average speed is defined as the ratio of total distance to the total time

it means

Average speed= total distance/total time

here total distance,

$D= 50m+40m\\D=90m$

and total time,

$t= 28s+40s\\t=70s$

therefore,

Average speed,

$S=\frac{D}{t}\\ S=\frac{90}{70}\\ S=1.29\frac{m}{s}$

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