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  1. G

    Dy/dx = (y^2) /x , form differential equation

    1. Homework Statement my ans is lnx = (-1/y) + c (-1/y) = lnx -c y = -1/ (lnx -c ) , but the answer given is (-1/ln x )+ C , how to get the answer given ? 2. Homework Equations 3. The Attempt at a Solution
  2. G

    Direction of shearing force

    1. Homework Statement why the shearing force acting on the object in the first diagram is in different direction , while in the second photo , it's in same direction ? 2. Homework Equations 3. The Attempt at a Solution in my opinion , it should be in different direction , because the...
  3. G

    Initial velocity

    1. Homework Statement how to know that the nozzle increases the velocity of water by 6 times? it's not given .... and no data for initial velocty given 2. Homework Equations 3. The Attempt at a Solution
  4. G

    Integrating factor

    1. Homework Statement is my integral R(x) and R(y) correct ? why it look so complicated ? 2. Homework Equations 3. The Attempt at a Solution
  5. G

    Cosh x / sinhx in the form of e^x

    1. Homework Statement I was told that coshx = (e^x + e^-x) / 2 , why cosh2x = (e^2x - e^-2x) / 2 ? 2. Homework Equations 3. The Attempt at a Solution
  6. G

    Second shift theorem

    1. Homework Statement why the f(t-1) isn't = 1-1 = 0 ? since f(t) = 1 , a=1 2. Homework Equations 3. The Attempt at a Solution
  7. G

    Density of ideal gas

    1. Homework Statement in this notes , i was told that the PV=mRT , why ? shouldn't PV= NRT , N=number of moles ? it should be PV = m/M (RT) , right ? 2. Homework Equations 3. The Attempt at a Solution
  8. G

    Second shift theorem

    1. Homework Statement for the alternative form of second shift property (4.8) , why he integral of (e^-sp) g(p+a) dp isn't equal to integral of (e^-sp) g(t) dp ? why it will become L{ g(t+a) } ? 2. Homework Equations 3. The Attempt at a Solution
  9. G

    Limit of series

    1. Homework Statement why we need to make x as absolute value ? as we can see, the original is x , why we we need to make x as absolute value ? is the working wrong ? 2. Homework Equations 3. The Attempt at a Solution
  10. G

    Center of pressure

    1. Homework Statement pls refer to photo 2 , (circled part) How to transform equation in 3-20 to become equation in 3-22a ? 2. Homework Equations 3. The Attempt at a Solution i have tried in photo 3 , yet can get the same form as in 3-22a . In step 2 , i divided the y_p with Fr
  11. G

    Vertical rise of liquid

    1. Homework Statement in the second picturre, why the zs1 and zs2 is calculated by using 2m and 0.6m respectively ? it should be 0.8m , am i right ? what's the purpose of the author to use 2m and 0.6m ? 2. Homework Equations 3. The Attempt at a Solution
  12. G

    Total energy of the flowing fluid

    1. Homework Statement Since this scanned notes is not clear enough , so I retype some parts of the notes, The enthalphy , h is given by the formula , h = u +Pv = u + P/ ρ I wanna ask about the total energy of the flowing fluid , which is given by the formula = P/ ρ + e = h + ke +pe = h +...
  13. G

    Finding pressure

    1. Homework Statement i couldn't understand why the pressure P1 is given by P atm - ρ water (gh2) - ρ(oil)(gh1) + ρ(mercury)(gh3) .Where is the point P1 ? It's not indicated in the diagram ... 2. Homework Equations 3. The Attempt at a Solution
  14. G

    Formula of weight of surface water

    1. Homework Statement Why the weight of water at water surface is given by formula 2(pi)Rσ(cos angle) ? 2. Homework Equations 3. The Attempt at a Solution
  15. G

    Shear stress of water

    1. Homework Statement for the second photo , why the dy is 0.005/2 ? why not 0.005 ? 2. Homework Equations 3. The Attempt at a Solution
  16. G

    Total forces acting downward on the plane

    1. Homework Statement I'm asked to find whether the object is moving or not in this question , i was given the solution like this , i am wondering why the tension from 100kg to the roller(up) and the tension from point B to roller doesnt cancel each other? Total force acting down the slope...
  17. G

    Forces on ramp

    1. The block of 50kg with m =30kg is in the verge of moving down the slope where theta = 20degree, determine the new value of m when the mass of block is increased more to 20kg . 2. Homework Equations 3. The Attempt at a Solution I have done in this way , is it okay ? (50-30)(9.81) =...
  18. G

    Ramp motion

    1. Homework Statement The block of weight of 100N is pulled by a rope over a pulley of small block with m kg . A 200N forec also acts horizontally as shown . If thge kinetic coefficient = 0.25 , static coefficient = 0.3 , determine whether the block is moving when the block is in moving or...
  19. G

    Equivalent resultant force

    1. Homework Statement i am asked to find the equivalent resultant force for this question . for the distributed load , i divided into 4 parts , is my method correct? 2. Homework Equations 3. The Attempt at a Solution total force about y = 6sin30 + 3(3) + (5-3)(0.5)(3) + 5(4) +...
  20. G

    Constraint of moment about an axis

    1. Homework Statement why there is no constraint of plate about a axis ? for moment about z -axis , i can have -2Bx +3By = 0 , where By and Bx = 0 which is shown in the top part of solution.... 2. Homework Equations 3. The Attempt at a Solution
  21. G

    Dot product

    1. Homework Statement why would we get 59N for FBa ? Isn't it equal to 50.6j +8.43k ? they are j and k respectively , how could they sum up together? since dot product of j dot j is j , k dot k is k 2. Homework Equations 3. The Attempt at a Solution
  22. G

    Determine the velocity after collision

    1. Homework Statement three small spheres, A , B and C with mass of 3kg , 4kg , 7kg respectively are arranged as shown in the figure. Initially , sphere B is placed in static condition,while the sphere A is moving with a velocity of 4u towards B and collides . Then , sphere C move to right with...
  23. G

    Determine the perpendicular distance for couple

    1. Homework Statement two 50N are applied to the corner B and D , determine the moment of couple formed by the two forces by resolving each force into the horizontal and vertical component and adding the two resulting couples . Use the result to determine the perpendicular distance between the...
  24. G

    Tension in negative value?

    1. Homework Statement Determine the tension cable A and B and the x , y , z reaction of the ball and socket joint at C . 2. Homework Equations 3. The Attempt at a Solution I let the reaction of ball and socket joint at C = Fx , Fy and Fz Sum of force in z direction : TA +TB +FZ= 400 Sum...
  25. G

    Force along u and v axes

    1. Homework Statement in this question , why cant i find Fu = 600cos 30= 520N ? why cant I find Fv = 600cos 120 = -300N ? 2. Homework Equations 3. The Attempt at a Solution Fu = 600cos 30= 520N ? Fv = 600cos 120 = -300N ?
  26. G

    Rotation about fixed axis

    in this notes , the author gave that the IG is the moment of inertia calculated about an axis which is perpendicular to the page ..... moment of inertia calculated about an axis which is perpendicular to the page here means id due to Ft(tangential force) only ? not include Fn ( normal force )...
  27. G

    Magnitude of acceleration

    1. Homework Statement can someone tell me why the acceleration in n direction is 18ms^-2 ? i only understand that the centripetal acceleration = 18ms^-2 2. Homework Equations 3. The Attempt at a Solution
  28. G

    Finding reaction and moment

    1. Homework Statement Lets say i have a structure like this , at A and B are fixed support ( it resists moment about , force in x and y direction) I wanna find the moment about the A , should I include the MA as well in my calculation or no ? 2. Homework Equations 3. The Attempt at a...
  29. G

    Reaction at pin support

    1. Homework Statement I'm asked to find the W and I was told that the rope at C is in tension , there is reaction at B , my question is , is there any reaction at C ? 2. Homework Equations 3. The Attempt at a Solution
  30. G

    Total forces acting downward on the plane

    1. Homework Statement the total force acting downwards the plane = 100(9.81)sin20 + 150= 485.5 N , should I take the tension in B into consideration ? how to get the tension on the rope ? 2. Homework Equations 3. The Attempt at a Solution
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