# Search results

1. ### Statics - Finding Reaction at Supports

Hey I'm just going over a past paper and I've lost the section of my notes RE this topic. I understand how to draw the free body diagram when there is a pin involved, but not when it is connected at 4 points, the fact that they're at an angle is not helping. Any help greatly appreciated...
2. ### Inertia of a pendulum with disc

A pendulum consists of a uniform thin rod of mass 5 kg and length 2 m to which is fixed a circular disc of mass 8 kg and radius 0.4 m. There is a pivot at one end. (a) Find the CoM and Moment of Inertia when the disc is: (i) half way along the rod; (ii) at the opposite end of the rod to the...
3. ### Hinged rod attached to elastic string

A rod (mass M, length L) hinged at point X. End Y is attached to X by an elastic string passing over a pin P, the natural length of the string is L. P is a distance L from X. Elastic Modulus of string: (1/4Mg) Refer to GPE to X and prove that total PE is: (1/4)MgL(1-cosθ-2sinθ) and find...
4. ### Horizontal Force in Pipe Bending

Homework Statement Water enters a pipe and goes through a bend with a contraction from 40mm to 25mm then into the atmosphere. What is the horizontal force required to hold the pipe in place? Homework Equations I have either been given the following or have calculated them using the standard...
5. ### Help solving a second order ODE with repeated roots, !

Help solving a second order ODE with repeated roots, urgent! I have a differential equaition d2y/dx2 - 6dy/dx + 9y = 0 I have found the general solution to be y = (Ax + B)e3x Now I need to find the solutions to A and B so that... when y = 4, x = 0 when y = 49.e15, x = 5 I...
6. ### How do I Solve these two equations?

As part of a question on axial load I need to simplify two equations in terms of P ([1] and [2]). http://img207.imageshack.us/img207/5757/77260215.png [Broken] In the above you can see how FBA and FBC were simplified to 0.8081P and 0.7143P respectively. I understand both the section...
7. ### Solution of exact differential equation

Hi, I'm looking at a past paper for an exam I have on Tuesday and I'm struggling to understand this question on exact derivatives. Here is a link to the question: http://imageshack.us/photo/my-images/812/questiong.png/ I have looked over my notes for guidance and eventually turned to the...
8. ### Solving the Differential

I have been asked to solve the differential equation: cotan(x)\stackrel{dy}{dx} = y-1 ey2 Using substitution on the right hand side and by integrating tan(x) on the left hand side the answer I have got is: ln|sec(x)| = - 0.5 e-y2 + C Is the answer ok to leave in this form? It has...
9. ### Using the theory of simultaneous equations

Homework Statement A, B, C and D are celebrating their joint birthdays and find that their ages add up to exactly 100 years. The sum of A's and D's ages equals the sum of B and C, while the di fference between the ages of A and D is twice C's age. Finally when D is as old as A is now, C...
10. ### Solving the Equation for a Complex Number

Homework Statement Solve the equation \overline{y} (y - 2) = 2\overline{y} + 15 - 8i for complex number y Homework Equations \overline{y}y = a2 + b2 The Attempt at a Solution a2+b2+8i-4ib-15=0 a2+b(b-4i)+8i-15=0 Pretty clueless where to go from here? Or if I've even gone in...
11. ### Calculating the corresponding percentage

Homework Statement A car is travelling at initial speed 5.5ms-1. The car is on a decline of 8o. The brakes are used and the car stops after travelling 10m along the road (with no skidding). At the moment when kinetic energy is 51% lower than the initial value, ﬁnd the corresponding...
12. ### Calculate the mass of ice with heat transfer / latent heat

Homework Statement Find mi, the initial mass of ice. Ti = -20 ci = 2093Jkg-1K-1 Ts = +35 ms = 2kg cs = 837.4Jkg-1K-1 cw = 4187Jkg-1K-1 lf = 3.35x105Jkg-1 S = solid W = water I = ice lf = latent heat of fusion of ice / water Homework Equations Q=mc\DeltaT Q=C\DeltaT Q=ml The Attempt at a...
13. ### Questions on Energy changes on a ball

Hi, this is a question from a past paper, for which I have the exam on Monday. Please see the attachments. Solutions a) w = fx =(20)(1.5-0.7) =16J b)PE=mgh ^PE=(.25)(10)(1.5)-(.25)(10)(.7) PE=2J c) ? when i attempted a solution i used ^KE=^PE this gave me an answer of v^2=30 I...