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- Thread starter XPFMember
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Give me five minutes. Ill help you outView attachment 57660

How to solve this question please??? I'm completely lost

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Give me five minutes. Ill help you out

View attachment 57660

How to solve this question please??? I'm completely lost

Last edited:

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please help me out with probability..it's really difficult to solve the complex ones..

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Inbox me all the questions you want done. Ill try my best to explainplease help me out with probability..it's really difficult to solve the complex ones..

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Thankyou soooooooo much!!Dm /dt = K(√M) cos (0.02t)

dM / √m = kcos0.02t dt

ʃ dM / √m = ʃ kcos0.02t dt

(M ^(1/2)) / (1/2) = ksin0.02t/0.02 + c

Rearrange:

2√M =(ksin0.02t)/0.02 + C

Now we have t = 0 and M = 100 so just substitute inorder to find the constant C

Therefore,

2√100 = (ksin0.02(0))/0.02 + C

2(10) = 0 + C

C = 20

Now : substitute the value of C to find the relationship.

2√M = (ksin0.02t)/0.02 +20

**1/0.02 = 50

So, it will become: 2√M = 50ksin0.02t + 20

b) M = 196 and t = 50

Just plug in the values.

2√196 = 50ksin0.02(50) +20

14*2 = 50ksin0.02(50) + 20

28 = 50ksin0.02(50) + 20

28 – 20 = 50ksin0.02(50)

8 = 50ksin(1)

8/50 = ksin(1)

K = 0.19 Ans.

c) 2√M = 50ksin0.02t + 20

Make m the subject

You will get:

M = ((50ksin0.02t + 20)/2)^2

Plus in the values.

M =((50(0.19)sin0.02t + 20)/2)^2

Solve the square. And you will get around 27 or 28 as your answer

If you still have problem, Inbox me

I dont own a cellphone otherwise a picture wouldve cleared it out well. Sorry

This is great! Your workings and steps are clear!!

Thanks a ton for your effort and time!!!

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No problem !! Im glad I helped!Thankyou soooooooo much!!

This is great! Your workings and steps are clear!!

Thanks a ton for your effort and time!!!

You can inbox me for more problems, Ill happily help ^_^

Stay blessed

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Not sure if this is correct, but hopefully it is.....

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y = e^(-x) sinx

For stationary point of any curve put dy/dx equal to 0

For dy/dx

Let u = e^(-x)

v = sinx

u’ = -e^(-x)

v’ = cosx

dy/dx = vu’ + uv’

You have all the values now. Just plug in.

0 = (sinx)(-e^(-x)) + (e^(-x))(cosx)

0 = e^(-x) {-sinx + cosx}

e^(-x) {-sinx + cosx} = 0

-sinx +cosx = 0

-sinx=-cosx

sinx=cosx

sinx/cosx = 0

tanx = 0

x = 45® or π/4 Ans.

b) For nature determination, Differentiate again. That will give you d2y/dx2

e^(-x) {-sinx + cosx}

d2y/dx2 = vu’ + uv’

u = e^(-x)

v = {-sinx + cosx}

u’ = -e^(-x)

v’ = -cosx –sinx

d2y/dx2 = vu’ + uv’

= [{-sinx + cosx}*-e^(-x) ]+[( e^(-x))*( -cosx –sinx)]

e^(-x)[sinx -cosx – cosx –sinx] = 0

[sinx -cosx – cosx –sinx] = 0

-2cosx = 0 Put x = 45 or π/4

-2(π/4) = 0

-π/2 < 0 Therefore this point is maximum

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First find the acceleration.Can someone please give me the final answer and working for this question.

Acceleration = (forces aiding acceleration - forces opposing acceleration)/ sum of masses

Here, Block A has higher mass so acceleration will be in the direction of A. In other words A will move down.

Therefore.

After resolving forces you will get acceleration = (40sin53 - 20sin37)/(4 + 2) = 10/3

Now, For tension. Remember when acceleration is downwards the equation to find tension is F - T = ma

So, just plug in the values. You can take any one block. A or B. Ill take A

40sin53 - T = (4)(10/3)

- T = 13.33 - 40sin53

- T = - 18.61

T = 18.61

Rounding off will give you 18.7 That is your option B

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If you sketch a velocity time graph. you will note that the slope of the curve will be constant since acceleration is constant. You will start from 0 (rest) and till 30m/s(final velocity)How to find the average velocity for this question?

Now, Average speed = total distance/total time.

Total distance

Therefore,

Average speed

t and t cancels out and you will get 15 as your answer. Choice C

If you sketch a velocity time graph. you will note that the slope of the curve will be constant since acceleration is constant. You will start from 0 (rest) and till 30m/s(final velocity)

Now, Average speed = total distance/total time.

Let time = t

Total distancewill be the area under the graph[1/2*(t)*(30)]

=

Therefore,

Average speed=[1/2*(t)*(30)]/t

t and t cancels out and you will get 15 as your answer. Choice C

Thanks alot. I have a doubt in one more question, if you are free.

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First step. Acceleration. As I stated in the previous question.Thanks alot. I have a doubt in one more question, if you are free.

Acceleration = (forces aiding acceleration - forces opposing acceleration)/ sum of masses

Now mass of m1 is greater than the mass of m2 so we'll just assume(for now) that m1 will move down since its heavier. (If true the resule should be positive)

Lets see.

Acceleration = (100sin37 - 80)/(10 + 8) = (60.2 - 80)/18 = -19.8/18 = -1.1

Now, The result is negative, It shouldve been positive therefore m1 will NOT move down even though its heavier. Acceleration came out negative because of the force, suggesting that m1 will move up the incline Choice A

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U = sin4xPLZ help with this !

Find the new limits.

1) X = π/24

U = sin4(π/24) = sin(π/6) = ½

2) X =0

U = sin4(0) = sin(0) = 0

Differentiate the substitution.

U = sin4x

Du/dx = 4cos4x

Find dx

Du = 4cos4x (dx)

Dx = du/4cos4x

Now re-write the expression

= ʃcos^3(4x) dx

You have value of dx

= ʃcos^3(4x) * (du/4cos4x)

Cancelling out will give you:

= ʃcos^2(4x)/4 du

= ¼ ʃ(1 – sin^2(4x) ) du

= ¼ ʃ(1 – u^2)

= ¼ [ u – (u^(3)/3) ]

= ¼ [(3u – u^3)/3)]

Put the limits

= ¼ {(3(0.5) – (0.5^(3))/3) – (3(0) – (0^3)/3)}

= ¼ {[(1.5 – 0.125)/3] – (0)}

= ¼ (1.375/3)

= ¼ (11/24)

= 11/96 Ans

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Thanks a lot !!U = sin4x

Find the new limits.

1) X = π/24

U = sin4(π/24) = sin(π/6) = ½

2) X =0

U = sin4(0) = sin(0) = 0

Differentiate the substitution.

U = sin4x

Du/dx = 4cos4x

Find dx

Du = 4cos4x (dx)

Dx = du/4cos4x

Now re-write the expression

= ʃcos^3(4x) dx

You have value of dx

= ʃcos^3(4x) * (du/4cos4x)

Cancelling out will give you:

= ʃcos^2(4x)/4 du

= ¼ ʃ(1 – sin^2(4x) ) du

= ¼ ʃ(1 – u^2)

= ¼ [ u – (u^(3)/3) ]

= ¼ [(3u – u^3)/3)]

Put the limits

= ¼ {(3(0.5) – (0.5^(3))/3) – (3(0) – (0^3)/3)}

= ¼ {[(1.5 – 0.125)/3] – (0)}

= ¼ (1.375/3)

= ¼ (11/24)

= 11/96 Ans

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