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    Transformation of Stress (Mech. Materials)

    Homework Statement Question is attached Homework Equations σ(x) = 0 σ(y)= P/A t(xy)= Tc/j The Attempt at a Solution I know how to do the stress transformation, but my only issue is noticing why σ(x)= 0, I cant see it, can someone help me.
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    Electric potential

    Homework Statement As an electron moves from a high potential to a low potential, its electric potential energy? a) increases b) remains the same c) decreases Homework Equations we know that V=U q0 the electric potential = potential energy times the charge. The...
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    Equilibrium of rigid bodies

    Homework Statement Determine the reaction at C. Homework Equations The Attempt at a Solution i know i have to take the moment about line DB and thus resulting in ƩM(DB)= λ(DA X F) + λ(DC X RC) =0 where λ = DB/ DB however the book solved it differently. they instead do...
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    Statics- equilibrium of rigid bodies

    Homework Statement An opening in a floor is covered by a 1×1.2-m sheet of plywood of mass 18 kg. The sheet is hinged at A and B and is maintained in a position slightly above the floor by a small block C. Determine the vertical component of the reaction (a) at A, (b) at B, (c) at C. Homework...
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    Comp Sci C++- while-loop

    C++-- while-loop Homework Statement calculate the 3 largest number of a sequence Homework Equations you ask the user to input a sequence of numbers, and enter the value 0 to stop entering numbers. c++ The Attempt at a Solution i managed to calculate the the maximum of the series of...
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    Net Electric field

    Homework Statement Figure 22-7a shows three particles with charges q1= +2Q, q2=-2Q, and q3 = -4Q, each a distance d from the origin. What net electric field E is produced at the origin? Homework Equations E=q/r^2* 1/(4∏ε0) The Attempt at a Solution So i calculated the of each particles...
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    How would I integrate?

    Homework Statement integrate 2t^(2)/(1+t^2)^(2) Homework Equations trig sub 1+tan^2(x)= sec^2(x) The Attempt at a Solution the attempted solution is attached.
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    Linear momentum

    Homework Statement Im not sure if I did this problem correctly, can someone please reassure me?! Homework Equations Conservation of Linear momentum pf=pi m1v1=m2v2 The Attempt at a Solution M(initial)=100,000 kg M(final)= 100,000kg-15,000kg= 85,000kg V(initial)=20.0m/s V(final)=...
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    Angular Momentum

    Homework Statement I am just confused about Angular momentum. Homework Equations KE(rotational)= 1/2Iw^2 Angular momentum= Iw The Attempt at a Solution Why can I do the change in KE rotational to calculate the her final angular velocity in 3 revs? very confused!! :( both equations relate...
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    Static Equilibrium and a wheel

    Homework Statement what magnitude of force applied horizontally at the axle of the wheel is necessary to wheel over an obstacle of height h = 0.108 m? The wheel's radius is r = 0.698 m and its mass is m = 1.71 kg. Homework Equations I know that in order to have a static equilibrium we...
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    Center of mass homework help

    Homework Statement Three uniform thin rods, each of length L = 22 cm, form an inverted U. The vertical cords each have a mass of 14 grams. The horizontal rod has a mass of 42 grams. What are the x coordinate and y coordinate of the system's center of mass? Homework Equations xcom=...
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    Conservation of Energy, pendulum problem

    Homework Statement To form a pendulum, a 0.092 kg ball is attached to one end of a rod of length 0.62 m and negligible mass, and the other end of the rod is mounted on a pivot. The rod is rotated until it is straight up, and then it is released from rest so that it swings down around the...
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    Relative velocity

    Homework Statement Ball 1 is dropped from rest at a height of 10m above the ground. at the same time, ball 2 is thrown straight upward from ground level with an initial speed of 10m/s. Homework Equations find the relative velocity of the balls when they pass each other at t=1...
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    Find a vector function that represents the curve of intersection of the two surfaces

    Homework Statement Find a vector function that represents the curve of intersection of the two surfaces: The cone z = sqrt( x^2 + y^2) and the plane z = 1+y. Homework Equations z = sqrt( x^2 + y^2) and the plane z = 1+y. The Attempt at a Solution This problem can be solved as...
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    Find the centroid of the solid in part (a).

    Homework Statement Find the volume of the solid that lies above the cone ϕ=pi/3 and below the sphere ρ=4cosϕ . Homework Equations Find the centroid of the solid in part (a). . The Attempt at a Solution For the volume I got 10pi which I am fairly sure is correct. I attempted trying to...
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    Calc 3! Moments and centers of mass

    Homework Statement Find the center of mass of a lamina in the shape of an isosceles right triangle with equal sides of length a if the density at any point is proportional to the square of the distance from the vertex opposite the hypotenuse. Homework Equations ∫∫ (f(x,y) dA mx= 1/m(∫∫...
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    Calorimetry synthesis gas

    Homework Statement The partial burning of coal in the presence of O2 and H2O produces a mixture of CO(g) and H2(g) called synthesis gas. This gas can be used to synthesize organic compounds, or it can be burned as a fuel. A typical synthesis gas consists of 55.0% CO(g), 33.0% H2(g) and 12.0%...
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    Specific heat of water

    Homework Statement What is the heat capacity of water in J*g*°C Homework Equations A 74.8 sample of copper at 143.2g is added to an insulated vessel containing 165ml of water, Density of water = 1.00 at 25.0 °C. The final temperature is 29.7° C The specific heat of copper is 0.385...