# Recent content by scrubber

1. ### Heat Transfer - finding rate of heat transfer

Q = (25-Tinner wall)/(Rth,inner) = (Tinner wall-TOuter wall)/(2.549) = (TOuter wall-10)/(Rth,outer) Q = (25-Tinner wall)/(0.0833) = (Tinner wall-TOuter wall)/(2.549) = (TOuter wall-10)/(0.0231) Is this what you mean?
2. ### Heat Transfer - finding rate of heat transfer

Rth,inner=1/(10*0.8*1.5)=0.0833W/m^2.K Rth,outer=1/(35*0.8*1.5)=0.0231W/m^2.K Like this?
3. ### Heat Transfer - finding rate of heat transfer

Homework Statement A 0.8m high and 1.5m wide double pane window consisting of two 3mm thick layers of glass(k=0.78W/mK) is separated by a 10mm wide stagnant air space(k=0.026 W/mK). The convection heat transfer coefficients on the inner and outer surfaces of the window are 10W/m^2K and 35W/m^2K...
4. ### Charged particles moved into a B-field

Homework Statement Two radioactive isotopes of singly charged plutonium(Pu-249 and Pu-244) are accelerated through a potential difference of 3.00kW and enter a uniform magnetic field of 1.50T directed perpendicular to their velocities. By performing relevat calculations, show that the ratio of...
5. ### Two long wires carrying current

Homework Statement Two long wires carrying current I1 and I2 in opposite directions pass through a closed path S as shown in the picture. What are the values of ∫B⋅ds and ∫E⋅ds if: i) I1=I2=1A ii) I1=1A and I2=0A? Homework Equations Ampere's Law: ∫B⋅ds=μ0I Faraday's Law: ∫E⋅ds=-dΦB/dt The...
6. ### 1D motion

Thanks for your reply. Do you mean I have to give the direction as well? The angles? For a), tanθ=100/5, θ=1.5° Therefore, the position is 100m 1.5° And for b), tanβ=16/5, β=1.3o Therefore, the average velocity is 5.9m/s 1.3° Like these?
7. ### Circular motion

Homework Statement A small ball of mass 0.50 kg is attached to a cord and perform uniform-speed circular motion of radius 2.0 m in a vertical plane. i) If the speed of the circular motion is 10m/s, determine the tension in the cord at the lowest point of the circular motion. ii)...
8. ### 1D motion

Homework Statement The position s (in metres) of a particle, as a function of time t (in seconds), is described by the equation s=5i+4r^2j. i and j are perpendicular unit vectors. a) Calculate the position of the particle at t=5. b) Determine the particle's average velocity between t=0 and...
9. ### Wave- displacement for a point

I got that now!!!! That means 2.63 t2 = 3/4∏, right? But still, the calculated t2 is 1.79, which is not 1.6 from the solution. Anything wrong?
10. ### Constrcutive interference

Homework Statement One speaker is located at the origin and the other is located at (x,y)=(0,3.00m). The speakers emit identical sound waves of wavelength 2.00m which are initially in phase. Where does constructive interference occur? ANS: x=1.50m The Attempt at a Solution...
11. ### Electric Potential & Electric Field

great! I understand now!! Sorry for the inconvenience. I will type them out next time. Thanks for your help :D
12. ### Wave- displacement for a point

270 degree, and why does the angle matter please?
13. ### Electric Potential & Electric Field

Homework Statement Three positive charges lie on the x-axis; q1 = 15 μC is at the origin, q2 = -30 μC is at x = 2 m, and q3 = 15 μC is a x = 3 m. ( please also refer to the attachment.) Find the electric potential and electric field at point “P” aroused from q1, q2 and q3. The Attempt at...
14. ### Wave- displacement for a point

Homework Statement A wave on a string has a wave function with the form of: y(x,t)=0.02sin(6.35x+2.63t) Find the shortest time for the displacement of the string at any point on the chain changes from 0.01m to -0.02m. The Attempt at a Solution The answer said we can set x=0. And...
15. ### R and I of DC circuit

For part b, can I rather use V=IR to find out the current through branches directly after finding out the total current?